Silent Circle moves away from NIST cryptographic standards, cites uncertainty

The U.S. National Security Agency's reported efforts to weaken encryption standards have prompted an encrypted communications company to move away from cryptographic algorithms sanctioned by the U.S. National Institute of Standards and Technology (NIST).

Silent Circle, a provider of encrypted mobile Voice over Internet Protocol (VoIP) and text messaging apps and services, will stop using the Advanced Encryption Standard (AES) cipher and Secure Hash Algorithm 2 (SHA-2) hash functions as default cryptographic algorithms in its products.

"We are going to replace our use of the AES cipher with the Twofish cipher, as it is a drop-in replacement," Silent Circle CTO Jon Callas said Monday in a blog post. "We are going to replace our use of the SHA-2 hash functions with the Skein hash function. We are also examining using the Threefish cipher where that makes sense." The company also plans to stop using P-384, one of the elliptic curves recommended by the NIST for use in elliptic curve cryptography (ECC).