diff --git a/book/source/03-cryptography.md b/book/source/03-cryptography.md
index 6673a8c..45d1fc7 100644
--- a/book/source/03-cryptography.md
+++ b/book/source/03-cryptography.md
@@ -23,10 +23,10 @@ Here are two important properties of cryptographic hash functions:
 
 Participants in symmetric-key operations need to exchange the shared secret over a secure channel.
 
-```{admonition} VISUAL
-:class: warning
-
-- visualization? (maybe a black key icon, following wikipedia's example?)
+```{figure} diag/symmetric_key.png
+---
+---
+A symmetric cryptographic key (which acts as a shared secret) 
 ```
 
 ### Benefits and downsides
@@ -80,7 +80,7 @@ Unlike symmetric cryptography, participants are not required to pre-arrange a sh
 
 Throughout this document, we will frequently reference asymmetric cryptographic key pairs:
 
-```{figure} diag/cryptographic_keypair.png
+```{figure} diag/asymmetric_keypair.png
 ---
 ---
 An asymmetric cryptographic key pair
@@ -90,7 +90,7 @@ Each key pair comprises two parts: the public key and the private key. For ease
 
 It's important to note that in many scenarios, only the public key is exposed or used (we will expand on these situations in subsequent sections):
 
-```{figure} diag/keypair_pub.png
+```{figure} diag/public_key.png
 ---
 ---
 The public parts of an asymmetric key pair