Malleability is the characteristic of some data or cryptographic elements (e.g., digital signatures or encrypted messages) to be altered by an unauthorized actor without modifying the underlying data.

It is a significant security risk as it could allow attackers to interfere with data and potentially create fraudulent transactions or exploit vulnerabilities without being detected. So, addressing and mitigating malleability issues can help ensure the trustworthiness and integrity of digital systems and communications.

How Malleability Works

Malleable Encryption Modes