diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/RevocationState.java b/pgpainless-core/src/main/java/org/pgpainless/algorithm/RevocationState.java
deleted file mode 100644
index 8e4a60d3..00000000
--- a/pgpainless-core/src/main/java/org/pgpainless/algorithm/RevocationState.java
+++ /dev/null
@@ -1,131 +0,0 @@
-// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package org.pgpainless.algorithm;
-
-import org.pgpainless.util.DateUtil;
-
-import javax.annotation.Nonnull;
-import java.util.Date;
-import java.util.NoSuchElementException;
-
-public final class RevocationState implements Comparable<RevocationState> {
-
-    private final RevocationStateType type;
-    private final Date date;
-
-    private RevocationState(RevocationStateType type) {
-        this(type, null);
-    }
-
-    private RevocationState(RevocationStateType type, Date date) {
-        this.type = type;
-        if (type == RevocationStateType.softRevoked && date == null) {
-            throw new NullPointerException("If type is 'softRevoked' then date cannot be null.");
-        }
-        this.date = date;
-    }
-
-    public static RevocationState notRevoked() {
-        return new RevocationState(RevocationStateType.notRevoked);
-    }
-
-    public static RevocationState softRevoked(@Nonnull Date date) {
-        return new RevocationState(RevocationStateType.softRevoked, date);
-    }
-
-    public static RevocationState hardRevoked() {
-        return new RevocationState(RevocationStateType.hardRevoked);
-    }
-
-    public RevocationStateType getType() {
-        return type;
-    }
-
-    public @Nonnull Date getDate() {
-        if (!isSoftRevocation()) {
-            throw new NoSuchElementException("RevocationStateType is not equal to 'softRevoked'. Cannot extract date.");
-        }
-        return date;
-    }
-
-    public boolean isHardRevocation() {
-        return getType() == RevocationStateType.hardRevoked;
-    }
-
-    public boolean isSoftRevocation() {
-        return getType() == RevocationStateType.softRevoked;
-    }
-
-    public boolean isNotRevoked() {
-        return getType() == RevocationStateType.notRevoked;
-    }
-
-    @Override
-    public String toString() {
-        String out = getType().toString();
-        if (isSoftRevocation()) {
-            out = out + " (" + DateUtil.formatUTCDate(date) + ")";
-        }
-        return out;
-    }
-
-    @Override
-    public int compareTo(@Nonnull RevocationState o) {
-        switch (getType()) {
-            case notRevoked:
-                if (o.isNotRevoked()) {
-                    return 0;
-                } else {
-                    return -1;
-                }
-
-            case softRevoked:
-                if (o.isNotRevoked()) {
-                    return 1;
-                } else if (o.isSoftRevocation()) {
-                    // Compare soft dates in reverse
-                    return o.getDate().compareTo(getDate());
-                } else {
-                    return -1;
-                }
-
-            case hardRevoked:
-                if (o.isHardRevocation()) {
-                    return 0;
-                } else {
-                    return 1;
-                }
-
-            default:
-                throw new AssertionError("Unknown type: " + type);
-        }
-    }
-
-    @Override
-    public int hashCode() {
-        return type.hashCode() * 31 + (isSoftRevocation() ? getDate().hashCode() : 0);
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (obj == null) {
-            return false;
-        }
-        if (this == obj) {
-            return true;
-        }
-        if (!(obj instanceof RevocationState)) {
-            return false;
-        }
-        RevocationState other = (RevocationState) obj;
-        if (getType() != other.getType()) {
-            return false;
-        }
-        if (isSoftRevocation()) {
-            return DateUtil.toSecondsPrecision(getDate()).getTime() == DateUtil.toSecondsPrecision(other.getDate()).getTime();
-        }
-        return true;
-    }
-}
diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/RevocationState.kt b/pgpainless-core/src/main/java/org/pgpainless/algorithm/RevocationState.kt
new file mode 100644
index 00000000..d5d95d45
--- /dev/null
+++ b/pgpainless-core/src/main/java/org/pgpainless/algorithm/RevocationState.kt
@@ -0,0 +1,87 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.algorithm
+
+import org.pgpainless.util.DateUtil
+import java.lang.AssertionError
+import java.util.*
+import kotlin.NoSuchElementException
+
+class RevocationState private constructor(
+        val type: RevocationStateType,
+        private val _date: Date?): Comparable<RevocationState> {
+
+    val date: Date
+        get() {
+            if (!isSoftRevocation()) {
+                throw NoSuchElementException("RevocationStateType is not equal to 'softRevoked'. Cannot extract date.")
+            }
+            return _date!!
+        }
+
+    private constructor(type: RevocationStateType): this(type, null)
+
+    fun isSoftRevocation() = type == RevocationStateType.softRevoked
+    fun isHardRevocation() = type == RevocationStateType.hardRevoked
+    fun isNotRevoked() = type == RevocationStateType.notRevoked
+
+    companion object {
+        @JvmStatic
+        fun notRevoked() = RevocationState(RevocationStateType.notRevoked)
+
+        @JvmStatic
+        fun softRevoked(date: Date) = RevocationState(RevocationStateType.softRevoked, date)
+
+        @JvmStatic
+        fun hardRevoked() = RevocationState(RevocationStateType.hardRevoked)
+    }
+
+    override fun compareTo(other: RevocationState): Int {
+        return when(type) {
+            RevocationStateType.notRevoked ->
+                if (other.isNotRevoked()) 0
+                else -1
+            RevocationStateType.softRevoked ->
+                if (other.isNotRevoked()) 1
+                // Compare soft dates in reverse
+                else if (other.isSoftRevocation()) other.date.compareTo(date)
+                else -1
+            RevocationStateType.hardRevoked ->
+                if (other.isHardRevocation()) 0
+                else 1
+            else -> throw AssertionError("Unknown type: $type")
+        }
+    }
+
+    override fun toString(): String {
+        return buildString {
+            append(type)
+            if (isSoftRevocation()) append(" (${DateUtil.formatUTCDate(date)})")
+        }
+    }
+
+    override fun hashCode(): Int {
+        return type.hashCode() * 31 + if (isSoftRevocation()) date.hashCode() else 0
+    }
+
+    override fun equals(other: Any?): Boolean {
+        if (other == null) {
+            return false
+        }
+        if (this === other) {
+            return true
+        }
+        if (other !is RevocationState) {
+            return false
+        }
+        if (type != other.type) {
+            return false
+        }
+        if (isSoftRevocation()) {
+            return DateUtil.toSecondsPrecision(date).time == DateUtil.toSecondsPrecision(other.date).time
+        }
+        return true
+    }
+}
\ No newline at end of file