diff --git a/external-sop/build.gradle b/external-sop/build.gradle
index 87b8e04..0f5055b 100644
--- a/external-sop/build.gradle
+++ b/external-sop/build.gradle
@@ -14,7 +14,9 @@ repositories {
 
 dependencies {
     testImplementation "org.junit.jupiter:junit-jupiter-api:$junitVersion"
+    testImplementation "org.junit.jupiter:junit-jupiter-params:$junitVersion"
     testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junitVersion"
+    testImplementation "com.google.code.gson:gson:2.10.1"
 
     api project(":sop-java")
 
@@ -30,4 +32,6 @@ dependencies {
 
 test {
     useJUnitPlatform()
+    // since we test external backends, we ignore test failures in this module
+    ignoreFailures = true
 }
\ No newline at end of file
diff --git a/external-sop/src/main/resources/sop/external/.gitignore b/external-sop/src/main/resources/sop/external/.gitignore
index b1790be..098eead 100644
--- a/external-sop/src/main/resources/sop/external/.gitignore
+++ b/external-sop/src/main/resources/sop/external/.gitignore
@@ -2,5 +2,4 @@
 #
 # SPDX-License-Identifier: CC0-1.0
 
-backend.local.properties
-backend.env
\ No newline at end of file
+config.json
\ No newline at end of file
diff --git a/external-sop/src/main/resources/sop/external/backend.properties b/external-sop/src/main/resources/sop/external/backend.properties
deleted file mode 100644
index 0cf721f..0000000
--- a/external-sop/src/main/resources/sop/external/backend.properties
+++ /dev/null
@@ -1,7 +0,0 @@
-# SPDX-FileCopyrightText: 2023 Paul Schaub <info@pgpainless.org>
-#
-# SPDX-License-Identifier: CC0-1.0
-
-## Do not change this file. To overwrite the SOP backend used during testing,
-##  simply create a file 'backend.local.properties' in this directory and override sop.backend in there.
-sop.backend=/path/to/backend
\ No newline at end of file
diff --git a/external-sop/src/main/resources/sop/external/config.json.example b/external-sop/src/main/resources/sop/external/config.json.example
new file mode 100644
index 0000000..a70980b
--- /dev/null
+++ b/external-sop/src/main/resources/sop/external/config.json.example
@@ -0,0 +1,17 @@
+{
+    "backends": [
+        {
+            "name": "Example-SOP",
+            "sop": "/usr/bin/example-sop"
+        },
+        {
+            "name": "Awesome-SOP",
+            "sop": "/usr/local/bin/awesome-sop",
+            "env": [
+                {
+                    "key": "myEnvironmentVariable", "value": "FooBar"
+                }
+            ]
+        }
+    ]
+}
\ No newline at end of file
diff --git a/external-sop/src/test/java/sop/external/AbstractExternalSOPTest.java b/external-sop/src/test/java/sop/external/AbstractExternalSOPTest.java
index 2781feb..3661d2a 100644
--- a/external-sop/src/test/java/sop/external/AbstractExternalSOPTest.java
+++ b/external-sop/src/test/java/sop/external/AbstractExternalSOPTest.java
@@ -4,174 +4,78 @@
 
 package sop.external;
 
-import org.apache.maven.artifact.versioning.ComparableVersion;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import com.google.gson.Gson;
+import org.junit.jupiter.api.Named;
+import org.junit.jupiter.params.provider.Arguments;
 import sop.SOP;
 
 import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.IOException;
 import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Properties;
+import java.util.stream.Stream;
 
 import static org.junit.jupiter.api.Assumptions.assumeFalse;
 import static org.junit.jupiter.api.Assumptions.assumeTrue;
 
 public abstract class AbstractExternalSOPTest {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(AbstractExternalSOPTest.class);
+    private static final List<Arguments> backends = new ArrayList<>();
 
-    private final SOP sop;
+    static {
+        TestSuite suite = readConfiguration();
+        assumeTrue(suite != null);
+        assumeFalse(suite.backends.isEmpty());
 
-    public AbstractExternalSOPTest() {
-        String backend = readSopBackendFromProperties();
-        assumeTrue(backend != null);
-        Properties environment = readBackendEnvironment();
-        sop = new ExternalSOP(backend, environment);
-    }
-
-    /**
-     * Return the SOP backend.
-     *
-     * @return SOP backend
-     */
-    public SOP getSop() {
-        return sop;
-    }
-
-    /**
-     * Return <pre>true</pre> iff the specified SOP backend binary is available and accessible.
-     *
-     * @return true if external SOP backend is usable
-     */
-    public static boolean isExternalSopInstalled() {
-        String binary = readSopBackendFromProperties();
-        if (binary == null) {
-            return false;
-        }
-        return new File(binary).exists();
-    }
-
-    /**
-     * Relational enum.
-     */
-    public enum Is {
-        /**
-         * Less than.
-         */
-        le("<"),
-        /**
-         * Less or equal than.
-         */
-        leq("<="),
-        /**
-         * Equal.
-         */
-        eq("=="),
-        /**
-         * Not equal.
-         */
-        neq("!="),
-        /**
-         * Greater or equal than.
-         */
-        geq(">="),
-        /**
-         * Greater than.
-         */
-        ge(">"),
-        ;
-
-        private final String display;
-
-        Is(String display) {
-            this.display = display;
-        }
-
-        public String toDisplay() {
-            return display;
-        }
-    }
-
-    /**
-     * Ignore a test if the tested binary version matches a version criterion.
-     * Example:
-     * If the installed version of example-sop is 0.1.3, <pre>ignoreIf("example-sop", Is.le, "0.1.4")</pre> will
-     * make the test be ignored.
-     * <pre>ignoreIf("example-sop", Is.eq, "0.1.3")</pre> will skip the test as well.
-     * <pre>ignoreIf("another-sop", Is.gt, "0.0.0")</pre> will not skip the test, since the binary name does not match.
-     *
-     * @param name name of the binary
-     * @param is relation of the version
-     * @param version the reference version
-     */
-    public void ignoreIf(String name, Is is, String version) {
-        String actualName = getSop().version().getName();
-        String actualVersion = getSop().version().getVersion();
-
-        if (!name.matches(actualName)) {
-            // Name mismatch, do not ignore
-            return;
-        }
-
-        ComparableVersion reference = new ComparableVersion(version);
-        ComparableVersion actual = new ComparableVersion(actualVersion);
-
-        int res = actual.compareTo(reference);
-        String msg = "Skip since installed " + name + " " + actual + " " + is.toDisplay() + " " + reference;
-        switch (is) {
-            case le:
-                assumeFalse(res < 0, msg);
-                break;
-            case leq:
-                assumeFalse(res <= 0, msg);
-            case eq:
-                assumeFalse(res == 0, msg);
-                break;
-            case neq:
-                assumeFalse(res != 0, msg);
-                break;
-            case geq:
-                assumeFalse(res >= 0, msg);
-                break;
-            case ge:
-                assumeFalse(res > 0, msg);
-                break;
-        }
-    }
-
-    static String readSopBackendFromProperties() {
-        Properties properties = new Properties();
-        try {
-            InputStream resourceIn = AbstractExternalSOPTest.class.getResourceAsStream("backend.local.properties");
-            if (resourceIn == null) {
-                LOGGER.info("Could not find backend.local.properties file. Try backend.properties instead.");
-                resourceIn = AbstractExternalSOPTest.class.getResourceAsStream("backend.properties");
-            }
-            if (resourceIn == null) {
-                throw new FileNotFoundException("Could not find backend.properties file.");
+        for (TestSubject subject : suite.backends) {
+            if (!new File(subject.sop).exists()) {
+                continue;
             }
 
-            properties.load(resourceIn);
-            return properties.getProperty("sop.backend");
-        } catch (IOException e) {
+            Properties env = new Properties();
+            if (subject.env != null) {
+                for (Var var : subject.env) {
+                    env.put(var.key, var.value);
+                }
+            }
+
+            SOP sop = new ExternalSOP(subject.sop, env);
+            backends.add(Arguments.of(Named.of(subject.name, sop)));
+        }
+    }
+
+    public static Stream<Arguments> provideBackends() {
+        return backends.stream();
+    }
+
+    public static TestSuite readConfiguration() {
+        Gson gson = new Gson();
+        InputStream inputStream = AbstractExternalSOPTest.class.getResourceAsStream("config.json");
+        if (inputStream == null) {
             return null;
         }
+
+        InputStreamReader reader = new InputStreamReader(inputStream);
+        TestSuite suite = gson.fromJson(reader, TestSuite.class);
+        return suite;
     }
 
-    protected static Properties readBackendEnvironment() {
-        Properties properties = new Properties();
-        try {
-            InputStream resourceIn = AbstractExternalSOPTest.class.getResourceAsStream("backend.env");
-            if (resourceIn == null) {
-                LOGGER.info("Could not read backend.env file.");
-            } else {
-                properties.load(resourceIn);
-            }
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
-        return properties;
+    // JSON DTOs
+
+    public static class TestSuite {
+        List<TestSubject> backends;
+    }
+
+    public static class TestSubject {
+        String name;
+        String sop;
+        List<Var> env;
+    }
+
+    public static class Var {
+        String key;
+        String value;
     }
 }
diff --git a/external-sop/src/test/java/sop/external/ExternalArmorDearmorRoundTripTest.java b/external-sop/src/test/java/sop/external/ExternalArmorDearmorRoundTripTest.java
index c4cd4ae..d6e4402 100644
--- a/external-sop/src/test/java/sop/external/ExternalArmorDearmorRoundTripTest.java
+++ b/external-sop/src/test/java/sop/external/ExternalArmorDearmorRoundTripTest.java
@@ -4,8 +4,9 @@
 
 package sop.external;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+import sop.SOP;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
@@ -16,7 +17,6 @@ import static sop.external.JUtils.arrayStartsWith;
 import static sop.external.JUtils.assertArrayStartsWith;
 import static sop.external.JUtils.assertAsciiArmorEquals;
 
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
 public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
 
     private static final String BEGIN_PGP_PRIVATE_KEY_BLOCK = "-----BEGIN PGP PRIVATE KEY BLOCK-----\n";
@@ -28,17 +28,18 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
     private static final String BEGIN_PGP_SIGNATURE = "-----BEGIN PGP SIGNATURE-----\n";
     private static final byte[] BEGIN_PGP_SIGNATURE_BYTES = BEGIN_PGP_SIGNATURE.getBytes(StandardCharsets.UTF_8);
 
-    @Test
-    public void dearmorArmorAliceKey() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void dearmorArmorAliceKey(SOP sop) throws IOException {
         byte[] aliceKey = TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8);
 
-        byte[] dearmored = getSop().dearmor()
+        byte[] dearmored = sop.dearmor()
                 .data(aliceKey)
                 .getBytes();
 
         assertFalse(arrayStartsWith(dearmored, BEGIN_PGP_PRIVATE_KEY_BLOCK_BYTES));
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(dearmored)
                 .getBytes();
 
@@ -46,17 +47,18 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
         assertAsciiArmorEquals(aliceKey, armored);
     }
 
-    @Test
-    public void dearmorArmorAliceCert() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void dearmorArmorAliceCert(SOP sop) throws IOException {
         byte[] aliceCert = TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] dearmored = getSop().dearmor()
+        byte[] dearmored = sop.dearmor()
                 .data(aliceCert)
                 .getBytes();
 
         assertFalse(arrayStartsWith(dearmored, BEGIN_PGP_PUBLIC_KEY_BLOCK_BYTES));
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(dearmored)
                 .getBytes();
 
@@ -64,17 +66,18 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
         assertAsciiArmorEquals(aliceCert, armored);
     }
 
-    @Test
-    public void dearmorArmorBobKey() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void dearmorArmorBobKey(SOP sop) throws IOException {
         byte[] bobKey = TestData.BOB_KEY.getBytes(StandardCharsets.UTF_8);
 
-        byte[] dearmored = getSop().dearmor()
+        byte[] dearmored = sop.dearmor()
                 .data(bobKey)
                 .getBytes();
 
         assertFalse(arrayStartsWith(dearmored, BEGIN_PGP_PRIVATE_KEY_BLOCK_BYTES));
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(dearmored)
                 .getBytes();
 
@@ -82,17 +85,18 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
         assertAsciiArmorEquals(bobKey, armored);
     }
 
-    @Test
-    public void dearmorArmorBobCert() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void dearmorArmorBobCert(SOP sop) throws IOException {
         byte[] bobCert = TestData.BOB_CERT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] dearmored = getSop().dearmor()
+        byte[] dearmored = sop.dearmor()
                 .data(bobCert)
                 .getBytes();
 
         assertFalse(arrayStartsWith(dearmored, BEGIN_PGP_PUBLIC_KEY_BLOCK_BYTES));
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(dearmored)
                 .getBytes();
 
@@ -100,17 +104,18 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
         assertAsciiArmorEquals(bobCert, armored);
     }
 
-    @Test
-    public void dearmorArmorCarolKey() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void dearmorArmorCarolKey(SOP sop) throws IOException {
         byte[] carolKey = TestData.CAROL_KEY.getBytes(StandardCharsets.UTF_8);
 
-        byte[] dearmored = getSop().dearmor()
+        byte[] dearmored = sop.dearmor()
                 .data(carolKey)
                 .getBytes();
 
         assertFalse(arrayStartsWith(dearmored, BEGIN_PGP_PRIVATE_KEY_BLOCK_BYTES));
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(dearmored)
                 .getBytes();
 
@@ -118,17 +123,18 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
         assertAsciiArmorEquals(carolKey, armored);
     }
 
-    @Test
-    public void dearmorArmorCarolCert() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void dearmorArmorCarolCert(SOP sop) throws IOException {
         byte[] carolCert = TestData.CAROL_CERT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] dearmored = getSop().dearmor()
+        byte[] dearmored = sop.dearmor()
                 .data(carolCert)
                 .getBytes();
 
         assertFalse(arrayStartsWith(dearmored, BEGIN_PGP_PUBLIC_KEY_BLOCK_BYTES));
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(dearmored)
                 .getBytes();
 
@@ -136,9 +142,9 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
         assertAsciiArmorEquals(carolCert, armored);
     }
 
-    @Test
-    public void dearmorArmorMessage() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // falsely reports Invalid Data Type
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void dearmorArmorMessage(SOP sop) throws IOException {
         byte[] message = ("-----BEGIN PGP MESSAGE-----\n" +
                 "\n" +
                 "wV4DR2b2udXyHrYSAQdAMZy9Iqb1IxszjI3v+TsfK//0lnJ9PKHDqVAB5ohp+RMw\n" +
@@ -147,13 +153,13 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
                 "CePQFpprprnGEzpE3flQLUc=\n" +
                 "=ZiFR\n" +
                 "-----END PGP MESSAGE-----\n").getBytes(StandardCharsets.UTF_8);
-        byte[] dearmored = getSop().dearmor()
+        byte[] dearmored = sop.dearmor()
                 .data(message)
                 .getBytes();
 
         assertFalse(arrayStartsWith(dearmored, BEGIN_PGP_MESSAGE_BYTES));
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(dearmored)
                 .getBytes();
 
@@ -161,8 +167,9 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
         assertAsciiArmorEquals(message, armored);
     }
 
-    @Test
-    public void dearmorArmorSignature() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void dearmorArmorSignature(SOP sop) throws IOException {
         byte[] signature = ("-----BEGIN PGP SIGNATURE-----\n" +
                 "\n" +
                 "wr0EABYKAG8FgmPBdRAJEPIxVQxPR+OORxQAAAAAAB4AIHNhbHRAbm90YXRpb25z\n" +
@@ -172,13 +179,13 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
                 "=GHvQ\n" +
                 "-----END PGP SIGNATURE-----\n").getBytes(StandardCharsets.UTF_8);
 
-        byte[] dearmored = getSop().dearmor()
+        byte[] dearmored = sop.dearmor()
                 .data(signature)
                 .getBytes();
 
         assertFalse(arrayStartsWith(dearmored, BEGIN_PGP_SIGNATURE_BYTES));
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(dearmored)
                 .getBytes();
 
@@ -186,23 +193,23 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
         assertAsciiArmorEquals(signature, armored);
     }
 
-    @Test
-    public void testDearmoringTwiceIsIdempotent() throws IOException {
-        ignoreIf("sqop", Is.eq, "0.27.2"); // IO error because: EOF
-
-        byte[] dearmored = getSop().dearmor()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void testDearmoringTwiceIsIdempotent(SOP sop) throws IOException {
+        byte[] dearmored = sop.dearmor()
                 .data(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .getBytes();
 
-        byte[] dearmoredAgain = getSop().dearmor()
+        byte[] dearmoredAgain = sop.dearmor()
                 .data(dearmored)
                 .getBytes();
 
         assertArrayEquals(dearmored, dearmoredAgain);
     }
 
-    @Test
-    public void testArmoringTwiceIsIdempotent() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void testArmoringTwiceIsIdempotent(SOP sop) throws IOException {
         byte[] armored = ("-----BEGIN PGP SIGNATURE-----\n" +
                 "\n" +
                 "wr0EABYKAG8FgmPBdRAJEPIxVQxPR+OORxQAAAAAAB4AIHNhbHRAbm90YXRpb25z\n" +
@@ -212,7 +219,7 @@ public class ExternalArmorDearmorRoundTripTest extends AbstractExternalSOPTest {
                 "=GHvQ\n" +
                 "-----END PGP SIGNATURE-----\n").getBytes(StandardCharsets.UTF_8);
 
-        byte[] armoredAgain = getSop().armor()
+        byte[] armoredAgain = sop.armor()
                 .data(armored)
                 .getBytes();
 
diff --git a/external-sop/src/test/java/sop/external/ExternalDecryptWithSessionKeyTest.java b/external-sop/src/test/java/sop/external/ExternalDecryptWithSessionKeyTest.java
index 0c1f7c7..7a5e4f6 100644
--- a/external-sop/src/test/java/sop/external/ExternalDecryptWithSessionKeyTest.java
+++ b/external-sop/src/test/java/sop/external/ExternalDecryptWithSessionKeyTest.java
@@ -4,10 +4,11 @@
 
 package sop.external;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 import sop.ByteArrayAndResult;
 import sop.DecryptionResult;
+import sop.SOP;
 import sop.SessionKey;
 
 import java.io.IOException;
@@ -16,7 +17,6 @@ import java.nio.charset.StandardCharsets;
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
 public class ExternalDecryptWithSessionKeyTest extends AbstractExternalSOPTest {
 
     private static final String CIPHERTEXT = "-----BEGIN PGP MESSAGE-----\n" +
@@ -29,9 +29,10 @@ public class ExternalDecryptWithSessionKeyTest extends AbstractExternalSOPTest {
             "-----END PGP MESSAGE-----\n";
     private static final String SESSION_KEY = "9:ED682800F5FEA829A82E8B7DDF8CE9CF4BF9BB45024B017764462EE53101C36A";
 
-    @Test
-    public void testDecryptAndExtractSessionKey() throws IOException {
-        ByteArrayAndResult<DecryptionResult> bytesAndResult = getSop().decrypt()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void testDecryptAndExtractSessionKey(SOP sop) throws IOException {
+        ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
                 .withKey(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .ciphertext(CIPHERTEXT.getBytes(StandardCharsets.UTF_8))
                 .toByteArrayAndResult();
@@ -41,9 +42,10 @@ public class ExternalDecryptWithSessionKeyTest extends AbstractExternalSOPTest {
         assertArrayEquals("Hello, World!\n".getBytes(StandardCharsets.UTF_8), bytesAndResult.getBytes());
     }
 
-    @Test
-    public void testDecryptWithSessionKey() throws IOException {
-        byte[] decrypted = getSop().decrypt()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void testDecryptWithSessionKey(SOP sop) throws IOException {
+        byte[] decrypted = sop.decrypt()
                 .withSessionKey(SessionKey.fromString(SESSION_KEY))
                 .ciphertext(CIPHERTEXT.getBytes(StandardCharsets.UTF_8))
                 .toByteArrayAndResult()
diff --git a/external-sop/src/test/java/sop/external/ExternalDetachedSignVerifyRoundTripTest.java b/external-sop/src/test/java/sop/external/ExternalDetachedSignVerifyRoundTripTest.java
index aaebe39..8e87b00 100644
--- a/external-sop/src/test/java/sop/external/ExternalDetachedSignVerifyRoundTripTest.java
+++ b/external-sop/src/test/java/sop/external/ExternalDetachedSignVerifyRoundTripTest.java
@@ -4,8 +4,9 @@
 
 package sop.external;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+import sop.SOP;
 import sop.Verification;
 import sop.enums.SignAs;
 import sop.exception.SOPGPException;
@@ -20,23 +21,23 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 import static sop.external.JUtils.assertArrayStartsWith;
 import static sop.external.JUtils.assertSignedBy;
 
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
 public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOPTest {
 
     private static final String BEGIN_PGP_SIGNATURE = "-----BEGIN PGP SIGNATURE-----\n";
     private static final byte[] BEGIN_PGP_SIGNATURE_BYTES = BEGIN_PGP_SIGNATURE.getBytes(StandardCharsets.UTF_8);
 
-    @Test
-    public void signVerifyWithAliceKey() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void signVerifyWithAliceKey(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] signature = getSop().detachedSign()
+        byte[] signature = sop.detachedSign()
                 .key(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .toByteArrayAndResult()
                 .getBytes();
 
-        List<Verification> verificationList = getSop().detachedVerify()
+        List<Verification> verificationList = sop.detachedVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(signature)
                 .data(message);
@@ -45,18 +46,19 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
         assertSignedBy(verificationList, TestData.ALICE_SIGNING_FINGERPRINT, TestData.ALICE_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void signVerifyTextModeWithAliceKey() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void signVerifyTextModeWithAliceKey(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] signature = getSop().detachedSign()
+        byte[] signature = sop.detachedSign()
                 .key(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .mode(SignAs.Text)
                 .data(message)
                 .toByteArrayAndResult()
                 .getBytes();
 
-        List<Verification> verificationList = getSop().detachedVerify()
+        List<Verification> verificationList = sop.detachedVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(signature)
                 .data(message);
@@ -65,12 +67,13 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
         assertSignedBy(verificationList, TestData.ALICE_SIGNING_FINGERPRINT, TestData.ALICE_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void verifyKnownMessageWithAliceCert() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void verifyKnownMessageWithAliceCert(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
         byte[] signature = TestData.ALICE_DETACHED_SIGNED_MESSAGE.getBytes(StandardCharsets.UTF_8);
 
-        List<Verification> verificationList = getSop().detachedVerify()
+        List<Verification> verificationList = sop.detachedVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(signature)
                 .data(message);
@@ -79,17 +82,18 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
         assertSignedBy(verificationList, TestData.ALICE_SIGNING_FINGERPRINT, TestData.ALICE_PRIMARY_FINGERPRINT, TestData.ALICE_DETACHED_SIGNED_MESSAGE_DATE);
     }
 
-    @Test
-    public void signVerifyWithBobKey() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void signVerifyWithBobKey(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] signature = getSop().detachedSign()
+        byte[] signature = sop.detachedSign()
                 .key(TestData.BOB_KEY.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .toByteArrayAndResult()
                 .getBytes();
 
-        List<Verification> verificationList = getSop().detachedVerify()
+        List<Verification> verificationList = sop.detachedVerify()
                 .cert(TestData.BOB_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(signature)
                 .data(message);
@@ -98,17 +102,18 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
         assertSignedBy(verificationList, TestData.BOB_SIGNING_FINGERPRINT, TestData.BOB_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void signVerifyWithCarolKey() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void signVerifyWithCarolKey(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] signature = getSop().detachedSign()
+        byte[] signature = sop.detachedSign()
                 .key(TestData.CAROL_KEY.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .toByteArrayAndResult()
                 .getBytes();
 
-        List<Verification> verificationList = getSop().detachedVerify()
+        List<Verification> verificationList = sop.detachedVerify()
                 .cert(TestData.CAROL_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(signature)
                 .data(message);
@@ -117,11 +122,12 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
         assertSignedBy(verificationList, TestData.CAROL_SIGNING_FINGERPRINT, TestData.CAROL_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void signVerifyWithEncryptedKey() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void signVerifyWithEncryptedKey(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] signature = getSop().detachedSign()
+        byte[] signature = sop.detachedSign()
                 .key(TestData.PASSWORD_PROTECTED_KEY.getBytes(StandardCharsets.UTF_8))
                 .withKeyPassword(TestData.PASSWORD)
                 .data(message)
@@ -130,7 +136,7 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
 
         assertArrayStartsWith(signature, BEGIN_PGP_SIGNATURE_BYTES);
 
-        List<Verification> verificationList = getSop().detachedVerify()
+        List<Verification> verificationList = sop.detachedVerify()
                 .cert(TestData.PASSWORD_PROTECTED_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(signature)
                 .data(message);
@@ -138,22 +144,23 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
         assertFalse(verificationList.isEmpty());
     }
 
-    @Test
-    public void signArmorVerifyWithBobKey() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void signArmorVerifyWithBobKey(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] signature = getSop().detachedSign()
+        byte[] signature = sop.detachedSign()
                 .key(TestData.BOB_KEY.getBytes(StandardCharsets.UTF_8))
                 .noArmor()
                 .data(message)
                 .toByteArrayAndResult()
                 .getBytes();
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(signature)
                 .getBytes();
 
-        List<Verification> verificationList = getSop().detachedVerify()
+        List<Verification> verificationList = sop.detachedVerify()
                 .cert(TestData.BOB_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(armored)
                 .data(message);
@@ -162,32 +169,30 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
         assertSignedBy(verificationList, TestData.BOB_SIGNING_FINGERPRINT, TestData.BOB_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void verifyNotAfterThrowsNoSignature() {
-        ignoreIf("sqop", Is.leq, "0.27.2"); // returns 1 instead of 3 (NO_SIGNATURE)
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void verifyNotAfterThrowsNoSignature(SOP sop) {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
         byte[] signature = TestData.ALICE_DETACHED_SIGNED_MESSAGE.getBytes(StandardCharsets.UTF_8);
         Date signatureDate = TestData.ALICE_DETACHED_SIGNED_MESSAGE_DATE;
         Date beforeSignature = new Date(signatureDate.getTime() - 1000); // 1 sec before sig
 
-        assertThrows(SOPGPException.NoSignature.class, () -> getSop().detachedVerify()
+        assertThrows(SOPGPException.NoSignature.class, () -> sop.detachedVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .notAfter(beforeSignature)
                 .signatures(signature)
                 .data(message));
     }
 
-    @Test
-    public void verifyNotBeforeThrowsNoSignature() {
-        ignoreIf("sqop", Is.leq, "0.27.2"); // returns 1 instead of 3 (NO_SIGNATURE)
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void verifyNotBeforeThrowsNoSignature(SOP sop) {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
         byte[] signature = TestData.ALICE_DETACHED_SIGNED_MESSAGE.getBytes(StandardCharsets.UTF_8);
         Date signatureDate = TestData.ALICE_DETACHED_SIGNED_MESSAGE_DATE;
         Date afterSignature = new Date(signatureDate.getTime() + 1000); // 1 sec after sig
 
-        assertThrows(SOPGPException.NoSignature.class, () -> getSop().detachedVerify()
+        assertThrows(SOPGPException.NoSignature.class, () -> sop.detachedVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .notBefore(afterSignature)
                 .signatures(signature)
@@ -195,24 +200,24 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
     }
 
 
-    @Test
-    public void signVerifyWithEncryptedKeyWithoutPassphraseFails() {
-        ignoreIf("sqop", Is.leq, "0.27.2"); // does not return exit code 67 for encrypted keys without passphrase
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void signVerifyWithEncryptedKeyWithoutPassphraseFails(SOP sop) {
         assertThrows(SOPGPException.KeyIsProtected.class, () ->
-                getSop().detachedSign()
+                sop.detachedSign()
                         .key(TestData.PASSWORD_PROTECTED_KEY.getBytes(StandardCharsets.UTF_8))
                         .data(TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8))
                         .toByteArrayAndResult()
                         .getBytes());
     }
 
-    @Test
-    public void signWithProtectedKeyAndMultiplePassphrasesTest()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void signWithProtectedKeyAndMultiplePassphrasesTest(SOP sop)
             throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] signature = getSop().sign()
+        byte[] signature = sop.sign()
                 .key(TestData.PASSWORD_PROTECTED_KEY.getBytes(StandardCharsets.UTF_8))
                 .withKeyPassword("wrong")
                 .withKeyPassword(TestData.PASSWORD) // correct
@@ -221,22 +226,20 @@ public class ExternalDetachedSignVerifyRoundTripTest extends AbstractExternalSOP
                 .toByteArrayAndResult()
                 .getBytes();
 
-        assertFalse(getSop().verify()
+        assertFalse(sop.verify()
                 .cert(TestData.PASSWORD_PROTECTED_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(signature)
                 .data(message)
                 .isEmpty());
     }
 
-    @Test
-    public void verifyMissingCertCausesMissingArg() {
-        ignoreIf("sqop", Is.leq, "0.27.3");
-        ignoreIf("PGPainless-SOP", Is.geq, "0.0.0"); // PGPainless uses picocli which throws
-        // UNSUPPORTED_OPTION for missing arg
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void verifyMissingCertCausesMissingArg(SOP sop) {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
         assertThrows(SOPGPException.MissingArg.class, () ->
-                getSop().verify()
+                sop.verify()
                         .signatures(TestData.ALICE_DETACHED_SIGNED_MESSAGE.getBytes(StandardCharsets.UTF_8))
                         .data(message));
     }
diff --git a/external-sop/src/test/java/sop/external/ExternalEncryptDecryptRoundTripTest.java b/external-sop/src/test/java/sop/external/ExternalEncryptDecryptRoundTripTest.java
index 2d6077e..2b505a4 100644
--- a/external-sop/src/test/java/sop/external/ExternalEncryptDecryptRoundTripTest.java
+++ b/external-sop/src/test/java/sop/external/ExternalEncryptDecryptRoundTripTest.java
@@ -4,10 +4,11 @@
 
 package sop.external;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 import sop.ByteArrayAndResult;
 import sop.DecryptionResult;
+import sop.SOP;
 import sop.Verification;
 import sop.enums.EncryptAs;
 import sop.exception.SOPGPException;
@@ -25,18 +26,18 @@ import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
 public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest {
 
-    @Test
-    public void encryptDecryptRoundTripPasswordTest() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void encryptDecryptRoundTripPasswordTest(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
-        byte[] ciphertext = getSop().encrypt()
+        byte[] ciphertext = sop.encrypt()
                 .withPassword("sw0rdf1sh")
                 .plaintext(message)
                 .getBytes();
 
-        byte[] plaintext = getSop().decrypt()
+        byte[] plaintext = sop.decrypt()
                 .withPassword("sw0rdf1sh")
                 .ciphertext(ciphertext)
                 .toByteArrayAndResult()
@@ -45,15 +46,16 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         assertArrayEquals(message, plaintext);
     }
 
-    @Test
-    public void encryptDecryptRoundTripAliceTest() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void encryptDecryptRoundTripAliceTest(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
-        byte[] ciphertext = getSop().encrypt()
+        byte[] ciphertext = sop.encrypt()
                 .withCert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .plaintext(message)
                 .getBytes();
 
-        ByteArrayAndResult<DecryptionResult> bytesAndResult = getSop().decrypt()
+        ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
                 .withKey(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .ciphertext(ciphertext)
                 .toByteArrayAndResult();
@@ -65,15 +67,16 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         assertNotNull(result.getSessionKey().get());
     }
 
-    @Test
-    public void encryptDecryptRoundTripBobTest() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void encryptDecryptRoundTripBobTest(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
-        byte[] ciphertext = getSop().encrypt()
+        byte[] ciphertext = sop.encrypt()
                 .withCert(TestData.BOB_CERT.getBytes(StandardCharsets.UTF_8))
                 .plaintext(message)
                 .getBytes();
 
-        byte[] plaintext = getSop().decrypt()
+        byte[] plaintext = sop.decrypt()
                 .withKey(TestData.BOB_KEY.getBytes(StandardCharsets.UTF_8))
                 .ciphertext(ciphertext)
                 .toByteArrayAndResult()
@@ -82,17 +85,16 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         assertArrayEquals(message, plaintext);
     }
 
-    @Test
-    public void encryptDecryptRoundTripCarolTest() throws IOException {
-        ignoreIf("sqop", Is.geq, "0.0.0"); // sqop reports cert not encryption capable
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void encryptDecryptRoundTripCarolTest(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
-        byte[] ciphertext = getSop().encrypt()
+        byte[] ciphertext = sop.encrypt()
                 .withCert(TestData.CAROL_CERT.getBytes(StandardCharsets.UTF_8))
                 .plaintext(message)
                 .getBytes();
 
-        byte[] plaintext = getSop().decrypt()
+        byte[] plaintext = sop.decrypt()
                 .withKey(TestData.CAROL_KEY.getBytes(StandardCharsets.UTF_8))
                 .ciphertext(ciphertext)
                 .toByteArrayAndResult()
@@ -101,22 +103,21 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         assertArrayEquals(message, plaintext);
     }
 
-    @Test
-    public void encryptNoArmorThenArmorThenDecryptRoundTrip() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // Invalid data type
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void encryptNoArmorThenArmorThenDecryptRoundTrip(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
-        byte[] ciphertext = getSop().encrypt()
+        byte[] ciphertext = sop.encrypt()
                 .withCert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .noArmor()
                 .plaintext(message)
                 .getBytes();
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(ciphertext)
                 .getBytes();
 
-        ByteArrayAndResult<DecryptionResult> bytesAndResult = getSop().decrypt()
+        ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
                 .withKey(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .ciphertext(armored)
                 .toByteArrayAndResult();
@@ -125,16 +126,17 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         assertArrayEquals(message, plaintext);
     }
 
-    @Test
-    public void encryptSignDecryptVerifyRoundTripAliceTest() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void encryptSignDecryptVerifyRoundTripAliceTest(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
-        byte[] ciphertext = getSop().encrypt()
+        byte[] ciphertext = sop.encrypt()
                 .withCert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .signWith(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .plaintext(message)
                 .getBytes();
 
-        ByteArrayAndResult<DecryptionResult> bytesAndResult = getSop().decrypt()
+        ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
                 .withKey(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .verifyWithCert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .ciphertext(ciphertext)
@@ -150,17 +152,18 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         assertTrue(verificationList.get(0).toString().contains("EB85BB5FA33A75E15E944E63F231550C4F47E38E EB85BB5FA33A75E15E944E63F231550C4F47E38E"));
     }
 
-    @Test
-    public void encryptSignAsTextDecryptVerifyRoundTripAliceTest() throws IOException {
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void encryptSignAsTextDecryptVerifyRoundTripAliceTest(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
-        byte[] ciphertext = getSop().encrypt()
+        byte[] ciphertext = sop.encrypt()
                 .withCert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .signWith(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .mode(EncryptAs.Text)
                 .plaintext(message)
                 .getBytes();
 
-        ByteArrayAndResult<DecryptionResult> bytesAndResult = getSop().decrypt()
+        ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
                 .withKey(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .verifyWithCert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .ciphertext(ciphertext)
@@ -176,29 +179,28 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         assertTrue(verificationList.get(0).toString().contains("EB85BB5FA33A75E15E944E63F231550C4F47E38E EB85BB5FA33A75E15E944E63F231550C4F47E38E"));
     }
 
-    @Test
-    public void encryptSignDecryptVerifyRoundTripWithFreshEncryptedKeyTest() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1");
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void encryptSignDecryptVerifyRoundTripWithFreshEncryptedKeyTest(SOP sop) throws IOException {
         byte[] keyPassword = "sw0rdf1sh".getBytes(StandardCharsets.UTF_8);
-        byte[] key = getSop().generateKey()
+        byte[] key = sop.generateKey()
                 .withKeyPassword(keyPassword)
                 .userId("Alice <alice@openpgp.org>")
                 .generate()
                 .getBytes();
-        byte[] cert = getSop().extractCert()
+        byte[] cert = sop.extractCert()
                 .key(key)
                 .getBytes();
 
         byte[] message = "Hello, World!\n".getBytes(StandardCharsets.UTF_8);
-        byte[] ciphertext = getSop().encrypt()
+        byte[] ciphertext = sop.encrypt()
                 .withCert(cert)
                 .signWith(key)
                 .withKeyPassword(keyPassword)
                 .plaintext(message)
                 .getBytes();
 
-        ByteArrayAndResult<DecryptionResult> bytesAndResult = getSop().decrypt()
+        ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
                 .withKey(key)
                 .withKeyPassword(keyPassword)
                 .verifyWithCert(cert)
@@ -209,11 +211,9 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         assertArrayEquals(message, bytesAndResult.getBytes());
     }
 
-    @Test
-    public void decryptVerifyNotAfterTest() {
-        ignoreIf("PGPainless-SOP", Is.le, "1.4.2"); // does not recognize --verify-not-after
-        ignoreIf("sqop", Is.leq, "0.27.2"); // does not throw NoSignature
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void decryptVerifyNotAfterTest(SOP sop) {
         byte[] message = ("-----BEGIN PGP MESSAGE-----\n" +
                 "\n" +
                 "wV4DR2b2udXyHrYSAQdAwlOwwyxFDJta5+H9abgSj8jum9v7etUc9usdrElESmow\n" +
@@ -231,7 +231,7 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         Date beforeSignature = new Date(signatureDate.getTime() - 1000); // 1 sec before signing date
 
         assertThrows(SOPGPException.NoSignature.class, () -> {
-            ByteArrayAndResult<DecryptionResult> bytesAndResult = getSop().decrypt()
+            ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
                     .withKey(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                     .verifyWithCert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                     .verifyNotAfter(beforeSignature)
@@ -244,11 +244,9 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         });
     }
 
-    @Test
-    public void decryptVerifyNotBeforeTest() {
-        ignoreIf("PGPainless-SOP", Is.le, "1.4.2"); // does not recognize --verify-not-after
-        ignoreIf("sqop", Is.leq, "0.27.2"); // does not throw NoSignature
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void decryptVerifyNotBeforeTest(SOP sop) {
         byte[] message = ("-----BEGIN PGP MESSAGE-----\n" +
                 "\n" +
                 "wV4DR2b2udXyHrYSAQdAwlOwwyxFDJta5+H9abgSj8jum9v7etUc9usdrElESmow\n" +
@@ -266,7 +264,7 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         Date afterSignature = new Date(signatureDate.getTime() + 1000); // 1 sec after signing date
 
         assertThrows(SOPGPException.NoSignature.class, () -> {
-            ByteArrayAndResult<DecryptionResult> bytesAndResult = getSop().decrypt()
+            ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
                     .withKey(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                     .verifyWithCert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                     .verifyNotBefore(afterSignature)
@@ -279,12 +277,12 @@ public class ExternalEncryptDecryptRoundTripTest extends AbstractExternalSOPTest
         });
     }
 
-    @Test
-    public void missingArgsTest() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.27.3");
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void missingArgsTest(SOP sop) {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        assertThrows(SOPGPException.MissingArg.class, () -> getSop().encrypt()
+        assertThrows(SOPGPException.MissingArg.class, () -> sop.encrypt()
                 .plaintext(message)
                 .getBytes());
     }
diff --git a/external-sop/src/test/java/sop/external/ExternalExtractCertTest.java b/external-sop/src/test/java/sop/external/ExternalExtractCertTest.java
index eca144b..39a661b 100644
--- a/external-sop/src/test/java/sop/external/ExternalExtractCertTest.java
+++ b/external-sop/src/test/java/sop/external/ExternalExtractCertTest.java
@@ -4,8 +4,9 @@
 
 package sop.external;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+import sop.SOP;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -16,58 +17,59 @@ import static sop.external.JUtils.arrayStartsWith;
 import static sop.external.JUtils.assertArrayStartsWith;
 import static sop.external.JUtils.assertAsciiArmorEquals;
 
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
 public class ExternalExtractCertTest extends AbstractExternalSOPTest {
 
     private static final String BEGIN_PGP_PUBLIC_KEY_BLOCK = "-----BEGIN PGP PUBLIC KEY BLOCK-----\n";
     private static final byte[] BEGIN_PGP_PUBLIC_KEY_BLOCK_BYTES = BEGIN_PGP_PUBLIC_KEY_BLOCK.getBytes(StandardCharsets.UTF_8);
 
-    @Test
-    public void extractArmoredCertFromArmoredKeyTest() throws IOException {
-        InputStream keyIn = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void extractArmoredCertFromArmoredKeyTest(SOP sop) throws IOException {
+        InputStream keyIn = sop.generateKey()
                 .userId("Alice <alice@openpgp.org>")
                 .generate()
                 .getInputStream();
 
-        byte[] cert = getSop().extractCert().key(keyIn).getBytes();
+        byte[] cert = sop.extractCert().key(keyIn).getBytes();
         assertArrayStartsWith(cert, BEGIN_PGP_PUBLIC_KEY_BLOCK_BYTES);
     }
 
-    @Test
-    public void extractAliceCertFromAliceKeyTest() throws IOException {
-        ignoreIf("PGPainless-SOP", Is.geq, "0.0.0"); // PGPainless uses old CTB
-        byte[] armoredCert = getSop().extractCert()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void extractAliceCertFromAliceKeyTest(SOP sop) throws IOException {
+        byte[] armoredCert = sop.extractCert()
                 .key(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .getBytes();
         assertAsciiArmorEquals(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8), armoredCert);
     }
 
-    @Test
-    public void extractBobsCertFromBobsKeyTest() throws IOException {
-        ignoreIf("PGPainless-SOP", Is.geq, "0.0.0"); // PGPainless uses old CTB
-        byte[] armoredCert = getSop().extractCert()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void extractBobsCertFromBobsKeyTest(SOP sop) throws IOException {
+        byte[] armoredCert = sop.extractCert()
                 .key(TestData.BOB_KEY.getBytes(StandardCharsets.UTF_8))
                 .getBytes();
         assertAsciiArmorEquals(TestData.BOB_CERT.getBytes(StandardCharsets.UTF_8), armoredCert);
     }
 
-    @Test
-    public void extractCarolsCertFromCarolsKeyTest() throws IOException {
-        ignoreIf("PGPainless-SOP", Is.geq, "0.0.0"); // PGPainless uses old CTB
-        byte[] armoredCert = getSop().extractCert()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void extractCarolsCertFromCarolsKeyTest(SOP sop) throws IOException {
+        byte[] armoredCert = sop.extractCert()
                 .key(TestData.CAROL_KEY.getBytes(StandardCharsets.UTF_8))
                 .getBytes();
         assertAsciiArmorEquals(TestData.CAROL_CERT.getBytes(StandardCharsets.UTF_8), armoredCert);
     }
 
-    @Test
-    public void extractUnarmoredCertFromArmoredKeyTest() throws IOException {
-        InputStream keyIn = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void extractUnarmoredCertFromArmoredKeyTest(SOP sop) throws IOException {
+        InputStream keyIn = sop.generateKey()
                 .userId("Alice <alice@openpgp.org>")
                 .generate()
                 .getInputStream();
 
-        byte[] cert = getSop().extractCert()
+        byte[] cert = sop.extractCert()
                 .noArmor()
                 .key(keyIn)
                 .getBytes();
@@ -75,30 +77,32 @@ public class ExternalExtractCertTest extends AbstractExternalSOPTest {
         assertFalse(arrayStartsWith(cert, BEGIN_PGP_PUBLIC_KEY_BLOCK_BYTES));
     }
 
-    @Test
-    public void extractArmoredCertFromUnarmoredKeyTest() throws IOException {
-        InputStream keyIn = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void extractArmoredCertFromUnarmoredKeyTest(SOP sop) throws IOException {
+        InputStream keyIn = sop.generateKey()
                 .userId("Alice <alice@openpgp.org>")
                 .noArmor()
                 .generate()
                 .getInputStream();
 
-        byte[] cert = getSop().extractCert()
+        byte[] cert = sop.extractCert()
                 .key(keyIn)
                 .getBytes();
 
         assertArrayStartsWith(cert, BEGIN_PGP_PUBLIC_KEY_BLOCK_BYTES);
     }
 
-    @Test
-    public void extractUnarmoredCertFromUnarmoredKeyTest() throws IOException {
-        InputStream keyIn = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void extractUnarmoredCertFromUnarmoredKeyTest(SOP sop) throws IOException {
+        InputStream keyIn = sop.generateKey()
                 .noArmor()
                 .userId("Alice <alice@openpgp.org>")
                 .generate()
                 .getInputStream();
 
-        byte[] cert = getSop().extractCert()
+        byte[] cert = sop.extractCert()
                 .noArmor()
                 .key(keyIn)
                 .getBytes();
diff --git a/external-sop/src/test/java/sop/external/ExternalGenerateKeyTest.java b/external-sop/src/test/java/sop/external/ExternalGenerateKeyTest.java
index 0e23992..7839c60 100644
--- a/external-sop/src/test/java/sop/external/ExternalGenerateKeyTest.java
+++ b/external-sop/src/test/java/sop/external/ExternalGenerateKeyTest.java
@@ -4,8 +4,9 @@
 
 package sop.external;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+import sop.SOP;
 
 import java.io.IOException;
 import java.nio.charset.Charset;
@@ -14,16 +15,16 @@ import java.nio.charset.StandardCharsets;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static sop.external.JUtils.assertArrayStartsWith;
 
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
 public class ExternalGenerateKeyTest extends AbstractExternalSOPTest {
 
     private static final Charset UTF8 = StandardCharsets.UTF_8;
     private static final String BEGIN_PGP_PRIVATE_KEY_BLOCK = "-----BEGIN PGP PRIVATE KEY BLOCK-----\n";
     byte[] BEGIN_PGP_PRIVATE_KEY_BLOCK_BYTES = BEGIN_PGP_PRIVATE_KEY_BLOCK.getBytes(UTF8);
 
-    @Test
-    public void generateKeyTest() throws IOException {
-        byte[] key = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void generateKeyTest(SOP sop) throws IOException {
+        byte[] key = sop.generateKey()
                 .userId("Alice <alice@openpgp.org>")
                 .generate()
                 .getBytes();
@@ -31,9 +32,10 @@ public class ExternalGenerateKeyTest extends AbstractExternalSOPTest {
         assertArrayStartsWith(key, BEGIN_PGP_PRIVATE_KEY_BLOCK_BYTES);
     }
 
-    @Test
-    public void generateKeyNoArmor() throws IOException {
-        byte[] key = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void generateKeyNoArmor(SOP sop) throws IOException {
+        byte[] key = sop.generateKey()
                 .userId("Alice <alice@openpgp.org>")
                 .noArmor()
                 .generate()
@@ -42,9 +44,10 @@ public class ExternalGenerateKeyTest extends AbstractExternalSOPTest {
         assertFalse(JUtils.arrayStartsWith(key, BEGIN_PGP_PRIVATE_KEY_BLOCK_BYTES));
     }
 
-    @Test
-    public void generateKeyWithMultipleUserIdsTest() throws IOException {
-        byte[] key = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void generateKeyWithMultipleUserIdsTest(SOP sop) throws IOException {
+        byte[] key = sop.generateKey()
                 .userId("Alice <alice@openpgp.org>")
                 .userId("Bob <bob@openpgp.org>")
                 .generate()
@@ -53,23 +56,20 @@ public class ExternalGenerateKeyTest extends AbstractExternalSOPTest {
         assertArrayStartsWith(key, BEGIN_PGP_PRIVATE_KEY_BLOCK_BYTES);
     }
 
-    @Test
-    public void generateKeyWithoutUserIdTest() throws IOException {
-        ignoreIf("pgpainless-cli", Is.le, "1.3.15");
-
-        byte[] key = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void generateKeyWithoutUserIdTest(SOP sop) throws IOException {
+        byte[] key = sop.generateKey()
                 .generate()
                 .getBytes();
 
         assertArrayStartsWith(key, BEGIN_PGP_PRIVATE_KEY_BLOCK_BYTES);
     }
 
-    @Test
-    public void generateKeyWithPasswordTest() throws IOException {
-        ignoreIf("sqop", Is.le, "0.27.0");
-        ignoreIf("pgpainless-cli", Is.le, "1.3.0");
-
-        byte[] key = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void generateKeyWithPasswordTest(SOP sop) throws IOException {
+        byte[] key = sop.generateKey()
                 .userId("Alice <alice@openpgp.org>")
                 .withKeyPassword("sw0rdf1sh")
                 .generate()
@@ -78,14 +78,10 @@ public class ExternalGenerateKeyTest extends AbstractExternalSOPTest {
         assertArrayStartsWith(key, BEGIN_PGP_PRIVATE_KEY_BLOCK_BYTES);
     }
 
-    @Test
-    public void generateKeyWithMultipleUserIdsAndPassword() throws IOException {
-        ignoreIf("sqop", Is.le, "0.27.0");
-        ignoreIf("PGPainless-SOP", Is.le, "1.3.15");
-        ignoreIf("PGPainless-SOP", Is.eq, "1.4.0");
-        ignoreIf("PGPainless-SOP", Is.eq, "1.4.1");
-
-        byte[] key = getSop().generateKey()
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void generateKeyWithMultipleUserIdsAndPassword(SOP sop) throws IOException {
+        byte[] key = sop.generateKey()
                 .userId("Alice <alice@openpgp.org>")
                 .userId("Bob <bob@openpgp.org>")
                 .withKeyPassword("sw0rdf1sh")
diff --git a/external-sop/src/test/java/sop/external/ExternalInlineSignDetachVerifyRoundTripTest.java b/external-sop/src/test/java/sop/external/ExternalInlineSignDetachVerifyRoundTripTest.java
index 41bc67c..a1e84b1 100644
--- a/external-sop/src/test/java/sop/external/ExternalInlineSignDetachVerifyRoundTripTest.java
+++ b/external-sop/src/test/java/sop/external/ExternalInlineSignDetachVerifyRoundTripTest.java
@@ -4,9 +4,10 @@
 
 package sop.external;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 import sop.ByteArrayAndResult;
+import sop.SOP;
 import sop.Signatures;
 import sop.Verification;
 
@@ -19,23 +20,21 @@ import static org.junit.jupiter.api.Assertions.assertFalse;
 import static sop.external.JUtils.arrayStartsWith;
 import static sop.external.JUtils.assertArrayStartsWith;
 
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
 public class ExternalInlineSignDetachVerifyRoundTripTest extends AbstractExternalSOPTest {
 
     private static final byte[] BEGIN_PGP_SIGNATURE = "-----BEGIN PGP SIGNATURE-----\n".getBytes(StandardCharsets.UTF_8);
 
-    @Test
-    public void inlineSignThenDetachThenDetachedVerifyTest() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void inlineSignThenDetachThenDetachedVerifyTest(SOP sop) throws IOException {
         byte[] message = "Hello, World!\n".getBytes(StandardCharsets.UTF_8);
 
-        byte[] inlineSigned = getSop().inlineSign()
+        byte[] inlineSigned = sop.inlineSign()
                 .key(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .getBytes();
 
-        ByteArrayAndResult<Signatures> bytesAndResult = getSop().inlineDetach()
+        ByteArrayAndResult<Signatures> bytesAndResult = sop.inlineDetach()
                 .message(inlineSigned)
                 .toByteArrayAndResult();
 
@@ -45,7 +44,7 @@ public class ExternalInlineSignDetachVerifyRoundTripTest extends AbstractExterna
         byte[] signatures = bytesAndResult.getResult()
                 .getBytes();
 
-        List<Verification> verifications = getSop().detachedVerify()
+        List<Verification> verifications = sop.detachedVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(signatures)
                 .data(plaintext);
@@ -53,18 +52,17 @@ public class ExternalInlineSignDetachVerifyRoundTripTest extends AbstractExterna
         assertFalse(verifications.isEmpty());
     }
 
-    @Test
-    public void inlineSignThenDetachNoArmorThenArmorThenDetachedVerifyTest() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void inlineSignThenDetachNoArmorThenArmorThenDetachedVerifyTest(SOP sop) throws IOException {
         byte[] message = "Hello, World!\n".getBytes(StandardCharsets.UTF_8);
 
-        byte[] inlineSigned = getSop().inlineSign()
+        byte[] inlineSigned = sop.inlineSign()
                 .key(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .getBytes();
 
-        ByteArrayAndResult<Signatures> bytesAndResult = getSop().inlineDetach()
+        ByteArrayAndResult<Signatures> bytesAndResult = sop.inlineDetach()
                 .noArmor()
                 .message(inlineSigned)
                 .toByteArrayAndResult();
@@ -76,12 +74,12 @@ public class ExternalInlineSignDetachVerifyRoundTripTest extends AbstractExterna
                 .getBytes();
         assertFalse(arrayStartsWith(signatures, BEGIN_PGP_SIGNATURE));
 
-        byte[] armored = getSop().armor()
+        byte[] armored = sop.armor()
                 .data(signatures)
                 .getBytes();
         assertArrayStartsWith(armored, BEGIN_PGP_SIGNATURE);
 
-        List<Verification> verifications = getSop().detachedVerify()
+        List<Verification> verifications = sop.detachedVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .signatures(armored)
                 .data(plaintext);
diff --git a/external-sop/src/test/java/sop/external/ExternalInlineSignVerifyTest.java b/external-sop/src/test/java/sop/external/ExternalInlineSignVerifyTest.java
index f0a632e..e6ee329 100644
--- a/external-sop/src/test/java/sop/external/ExternalInlineSignVerifyTest.java
+++ b/external-sop/src/test/java/sop/external/ExternalInlineSignVerifyTest.java
@@ -4,9 +4,10 @@
 
 package sop.external;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 import sop.ByteArrayAndResult;
+import sop.SOP;
 import sop.Verification;
 import sop.enums.InlineSignAs;
 import sop.exception.SOPGPException;
@@ -21,7 +22,6 @@ import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static sop.external.JUtils.assertSignedBy;
 
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
 public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
 
     private static final String BEGIN_PGP_MESSAGE = "-----BEGIN PGP MESSAGE-----\n";
@@ -29,20 +29,19 @@ public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
     private static final String BEGIN_PGP_SIGNED_MESSAGE = "-----BEGIN PGP SIGNED MESSAGE-----\n";
     private static final byte[] BEGIN_PGP_SIGNED_MESSAGE_BYTES = BEGIN_PGP_SIGNED_MESSAGE.getBytes(StandardCharsets.UTF_8);
 
-    @Test
-    public void inlineSignVerifyAlice() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void inlineSignVerifyAlice(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] inlineSigned = getSop().inlineSign()
+        byte[] inlineSigned = sop.inlineSign()
                 .key(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .getBytes();
 
         JUtils.assertArrayStartsWith(inlineSigned, BEGIN_PGP_MESSAGE_BYTES);
 
-        ByteArrayAndResult<List<Verification>> bytesAndResult = getSop().inlineVerify()
+        ByteArrayAndResult<List<Verification>> bytesAndResult = sop.inlineVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .data(inlineSigned)
                 .toByteArrayAndResult();
@@ -52,13 +51,12 @@ public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
         assertSignedBy(verificationList, TestData.ALICE_SIGNING_FINGERPRINT, TestData.ALICE_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void inlineSignVerifyAliceNoArmor() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void inlineSignVerifyAliceNoArmor(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] inlineSigned = getSop().inlineSign()
+        byte[] inlineSigned = sop.inlineSign()
                 .key(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .noArmor()
                 .data(message)
@@ -66,7 +64,7 @@ public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
 
         assertFalse(JUtils.arrayStartsWith(inlineSigned, BEGIN_PGP_MESSAGE_BYTES));
 
-        ByteArrayAndResult<List<Verification>> bytesAndResult = getSop().inlineVerify()
+        ByteArrayAndResult<List<Verification>> bytesAndResult = sop.inlineVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .data(inlineSigned)
                 .toByteArrayAndResult();
@@ -76,13 +74,12 @@ public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
         assertSignedBy(verificationList, TestData.ALICE_SIGNING_FINGERPRINT, TestData.ALICE_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void clearsignVerifyAlice() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void clearsignVerifyAlice(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] clearsigned = getSop().inlineSign()
+        byte[] clearsigned = sop.inlineSign()
                 .key(TestData.ALICE_KEY.getBytes(StandardCharsets.UTF_8))
                 .mode(InlineSignAs.clearsigned)
                 .data(message)
@@ -90,7 +87,7 @@ public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
 
         JUtils.assertArrayStartsWith(clearsigned, BEGIN_PGP_SIGNED_MESSAGE_BYTES);
 
-        ByteArrayAndResult<List<Verification>> bytesAndResult = getSop().inlineVerify()
+        ByteArrayAndResult<List<Verification>> bytesAndResult = sop.inlineVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .data(clearsigned)
                 .toByteArrayAndResult();
@@ -100,15 +97,13 @@ public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
         assertSignedBy(verificationList, TestData.ALICE_SIGNING_FINGERPRINT, TestData.ALICE_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void inlineVerifyCompareSignatureDate() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-        ignoreIf("sqop", Is.leq, "0.27.2"); // returns 1 instead of 3 (NO_SIGNATURE)
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void inlineVerifyCompareSignatureDate(SOP sop) throws IOException {
         byte[] message = TestData.ALICE_INLINE_SIGNED_MESSAGE.getBytes(StandardCharsets.UTF_8);
         Date signatureDate = TestData.ALICE_INLINE_SIGNED_MESSAGE_DATE;
 
-        ByteArrayAndResult<List<Verification>> bytesAndResult = getSop().inlineVerify()
+        ByteArrayAndResult<List<Verification>> bytesAndResult = sop.inlineVerify()
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .toByteArrayAndResult();
@@ -116,52 +111,47 @@ public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
         assertSignedBy(verificationList, TestData.ALICE_SIGNING_FINGERPRINT, TestData.ALICE_PRIMARY_FINGERPRINT, signatureDate);
     }
 
-    @Test
-    public void assertNotBeforeThrowsNoSignature() {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-        ignoreIf("sqop", Is.leq, "0.27.2"); // returns 1 instead of 3 (NO_SIGNATURE)
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void assertNotBeforeThrowsNoSignature(SOP sop) {
         byte[] message = TestData.ALICE_INLINE_SIGNED_MESSAGE.getBytes(StandardCharsets.UTF_8);
         Date signatureDate = TestData.ALICE_INLINE_SIGNED_MESSAGE_DATE;
         Date afterSignature = new Date(signatureDate.getTime() + 1000); // 1 sec before sig
 
-        assertThrows(SOPGPException.NoSignature.class, () -> getSop().inlineVerify()
+        assertThrows(SOPGPException.NoSignature.class, () -> sop.inlineVerify()
                 .notBefore(afterSignature)
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .toByteArrayAndResult());
     }
 
-    @Test
-    public void assertNotAfterThrowsNoSignature() {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-        ignoreIf("sqop", Is.leq, "0.27.2"); // returns 1 instead of 3 (NO_SIGNATURE)
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void assertNotAfterThrowsNoSignature(SOP sop) {
         byte[] message = TestData.ALICE_INLINE_SIGNED_MESSAGE.getBytes(StandardCharsets.UTF_8);
         Date signatureDate = TestData.ALICE_INLINE_SIGNED_MESSAGE_DATE;
         Date beforeSignature = new Date(signatureDate.getTime() - 1000); // 1 sec before sig
 
-        assertThrows(SOPGPException.NoSignature.class, () -> getSop().inlineVerify()
+        assertThrows(SOPGPException.NoSignature.class, () -> sop.inlineVerify()
                 .notAfter(beforeSignature)
                 .cert(TestData.ALICE_CERT.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .toByteArrayAndResult());
     }
 
-    @Test
-    public void inlineSignVerifyBob() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void inlineSignVerifyBob(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] inlineSigned = getSop().inlineSign()
+        byte[] inlineSigned = sop.inlineSign()
                 .key(TestData.BOB_KEY.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .getBytes();
 
         JUtils.assertArrayStartsWith(inlineSigned, BEGIN_PGP_MESSAGE_BYTES);
 
-        ByteArrayAndResult<List<Verification>> bytesAndResult = getSop().inlineVerify()
+        ByteArrayAndResult<List<Verification>> bytesAndResult = sop.inlineVerify()
                 .cert(TestData.BOB_CERT.getBytes(StandardCharsets.UTF_8))
                 .data(inlineSigned)
                 .toByteArrayAndResult();
@@ -171,20 +161,19 @@ public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
         assertSignedBy(verificationList, TestData.BOB_SIGNING_FINGERPRINT, TestData.BOB_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void inlineSignVerifyCarol() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void inlineSignVerifyCarol(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] inlineSigned = getSop().inlineSign()
+        byte[] inlineSigned = sop.inlineSign()
                 .key(TestData.CAROL_KEY.getBytes(StandardCharsets.UTF_8))
                 .data(message)
                 .getBytes();
 
         JUtils.assertArrayStartsWith(inlineSigned, BEGIN_PGP_MESSAGE_BYTES);
 
-        ByteArrayAndResult<List<Verification>> bytesAndResult = getSop().inlineVerify()
+        ByteArrayAndResult<List<Verification>> bytesAndResult = sop.inlineVerify()
                 .cert(TestData.CAROL_CERT.getBytes(StandardCharsets.UTF_8))
                 .data(inlineSigned)
                 .toByteArrayAndResult();
@@ -194,20 +183,19 @@ public class ExternalInlineSignVerifyTest extends AbstractExternalSOPTest {
         assertSignedBy(verificationList, TestData.CAROL_SIGNING_FINGERPRINT, TestData.CAROL_PRIMARY_FINGERPRINT);
     }
 
-    @Test
-    public void inlineSignVerifyProtectedKey() throws IOException {
-        ignoreIf("sqop", Is.leq, "0.26.1"); // inline-sign not supported
-
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void inlineSignVerifyProtectedKey(SOP sop) throws IOException {
         byte[] message = TestData.PLAINTEXT.getBytes(StandardCharsets.UTF_8);
 
-        byte[] inlineSigned = getSop().inlineSign()
+        byte[] inlineSigned = sop.inlineSign()
                 .withKeyPassword(TestData.PASSWORD)
                 .key(TestData.PASSWORD_PROTECTED_KEY.getBytes(StandardCharsets.UTF_8))
                 .mode(InlineSignAs.binary)
                 .data(message)
                 .getBytes();
 
-        ByteArrayAndResult<List<Verification>> bytesAndResult = getSop().inlineVerify()
+        ByteArrayAndResult<List<Verification>> bytesAndResult = sop.inlineVerify()
                 .cert(TestData.PASSWORD_PROTECTED_CERT.getBytes(StandardCharsets.UTF_8))
                 .data(inlineSigned)
                 .toByteArrayAndResult();
diff --git a/external-sop/src/test/java/sop/external/ExternalVersionTest.java b/external-sop/src/test/java/sop/external/ExternalVersionTest.java
index bde6cb5..0415d03 100644
--- a/external-sop/src/test/java/sop/external/ExternalVersionTest.java
+++ b/external-sop/src/test/java/sop/external/ExternalVersionTest.java
@@ -4,38 +4,42 @@
 
 package sop.external;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+import sop.SOP;
 
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
 public class ExternalVersionTest extends AbstractExternalSOPTest {
 
-    @Test
-    public void versionNameTest() {
-        String name = getSop().version().getName();
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void versionNameTest(SOP sop) {
+        String name = sop.version().getName();
         assertNotNull(name);
         assertFalse(name.isEmpty());
     }
 
-    @Test
-    public void versionVersionTest() {
-        String version = getSop().version().getVersion();
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void versionVersionTest(SOP sop) {
+        String version = sop.version().getVersion();
         assertTrue(version.matches("\\d+(\\.\\d+)*\\S*"));
     }
 
-    @Test
-    public void backendVersionTest() {
-        String backend = getSop().version().getBackendVersion();
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void backendVersionTest(SOP sop) {
+        String backend = sop.version().getBackendVersion();
         assertFalse(backend.isEmpty());
     }
 
-    @Test
-    public void extendedVersionTest() {
-        String extended = getSop().version().getExtendedVersion();
+    @ParameterizedTest
+    @MethodSource("sop.external.AbstractExternalSOPTest#provideBackends")
+    public void extendedVersionTest(SOP sop) {
+        String extended = sop.version().getExtendedVersion();
         assertFalse(extended.isEmpty());
     }
 
diff --git a/external-sop/src/test/java/sop/external/UnsupportedSubcommandTest.java b/external-sop/src/test/java/sop/external/UnsupportedSubcommandTest.java
deleted file mode 100644
index 55e13e2..0000000
--- a/external-sop/src/test/java/sop/external/UnsupportedSubcommandTest.java
+++ /dev/null
@@ -1,58 +0,0 @@
-// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package sop.external;
-
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.EnabledIf;
-import sop.exception.SOPGPException;
-
-import java.io.IOException;
-import java.util.Properties;
-
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assumptions.assumeTrue;
-
-@EnabledIf("sop.external.AbstractExternalSOPTest#isExternalSopInstalled")
-public class UnsupportedSubcommandTest extends AbstractExternalSOPTest {
-
-    private final UnsupportedSubcommandExternal unsupportedSubcommand;
-
-    public UnsupportedSubcommandTest() {
-        String backend = readSopBackendFromProperties();
-        assumeTrue(backend != null);
-        Properties environment = readBackendEnvironment();
-        unsupportedSubcommand = new UnsupportedSubcommandExternal(backend, environment);
-    }
-
-    @Test
-    public void testUnsupportedSubcommand() {
-        // "sop unsupported" returns error code UNSUPPORTED_SUBCOMMAND
-        assertThrows(SOPGPException.UnsupportedSubcommand.class,
-                unsupportedSubcommand::executeUnsupportedSubcommand);
-    }
-
-    private static class UnsupportedSubcommandExternal {
-
-        private final Runtime runtime = Runtime.getRuntime();
-        private final String binary;
-        private final Properties environment;
-
-        UnsupportedSubcommandExternal(String binaryName, Properties environment) {
-            this.binary = binaryName;
-            this.environment = environment;
-        }
-
-        public void executeUnsupportedSubcommand() {
-            String[] command = new String[] {binary, "unsupported"}; // ~$ sop unsupported
-            String[] env = ExternalSOP.propertiesToEnv(environment).toArray(new String[0]);
-            try {
-                Process process = runtime.exec(command, env);
-                ExternalSOP.finish(process);
-            } catch (IOException e) {
-                throw new RuntimeException(e);
-            }
-        }
-    }
-}