diff --git a/OWASP test questions.md b/OWASP test questions.md
index 9df478c..abda1c9 100644
--- a/OWASP test questions.md	
+++ b/OWASP test questions.md	
@@ -24,6 +24,7 @@ https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html
 * Describe the circumstances under which any web browser released after 2020 would accept a SHA-1 signed TLS certificate, if any.
 * Is an extended validation TLS certificate more cryptographically secure than a normally issued TLS certificate?
 * What is Let's Encrypt, and what incident caused the project to be founded?
+* What is a rainbow table?
 * What is a cryptographic salt?
 * What is a cryptographic pepper?
 * Describe how to store and manage a cryptographic pepper in the context of multiple web servers sharing the same database, and backups.  You may assume the web servers and backups are managed by trusted personnel.