Secret Suffix Forgery Attack

An attack against Secret Suffix MAC. Involves finding a Hash Collision between the original messages. $\text{Hash}({\text{M}}_1)=\text{Hash}({\text{M}}_2)⟹{\text{MAC}}_{key}(M_1)={\text{MAC}}_{key}(M_2)$

https://eitca.org/cybersecurity/eitc-is-acc-advanced-classical-cryptography/message-authentication-codes/mac-message-authentication-codes-and-hmac/examination-review-mac-message-authentication-codes-and-hmac/what-are-the-weaknesses-of-the-secret-prefix-and-secret-suffix-methods-for-constructing-macs/