diff --git a/book/source/17-zoom_certificates.md b/book/source/17-zoom_certificates.md
index 1aa15a8..ca204ea 100644
--- a/book/source/17-zoom_certificates.md
+++ b/book/source/17-zoom_certificates.md
@@ -170,6 +170,11 @@ The packet type ID ("6") defines the semantics of the following data within the
 
 Note that the *Public-Key packet* contains only the public part of the key.
 
+```{figure} diag/public-key_packet.png
+
+Structure of a Public-Key packet.
+```
+
 (zooming_in_dks)=
 ### Direct Key Signature
 
@@ -355,6 +360,11 @@ The hash digest is calculated from the following data (see [Computing Signatures
 
 The signature is calculated from this hash digest.
 
+```{figure} diag/direct_key_signature_packet.png
+
+Structure of a direct key signature packet.
+```
+
 (zoom_enc_subkey)=
 ## Encryption subkey