NSA Suite B Cryptography

NSA Suite B Cryptography was a set of cryptographic algorithms promulgated by the National Security Agency as part of its Cryptographic Modernization Program. It was to serve as an interoperable cryptographic base for both unclassified information and most classified information.

Suite B was announced on 16 February 2005. A corresponding set of unpublished algorithms, Suite A, is "used in applications where Suite B may not be appropriate. Both Suite A and Suite B can be used to protect foreign releasable information, US-Only information, and Sensitive Compartmented Information (SCI)."

In 2018, NSA replaced Suite B with the Commercial National Security Algorithm Suite (CNSA).

Suite B's components were:

• Advanced Encryption Standard (AES) with key sizes of 128 and 256 bits. For traffic flow, AES should be used with either the Counter Mode (CTR) for low bandwidth traffic or the Galois/Counter Mode (GCM) mode of operation for high bandwidth traffic (see Block cipher modes of operation) – symmetric encryption
• Elliptic Curve Digital Signature Algorithm (ECDSA) – digital signatures
• Elliptic Curve Diffie–Hellman (ECDH) – key agreement
• Secure Hash Algorithm 2 (SHA-256 and SHA-384) – message digest