The following is a breif explination of the cryptological algorithms, modes and key sizes used in the Secure Channel family of products.
The Secure Channel family uses the Advanced Encryption Standard (AES) with a 256 bit key. This is one of the strongest symetric key algorithms available. It has been approved by the National Security Agency for use in safeguarding U.S. Government data.
As user supplied passwords generally have low entropy and are very vulnerable to pre computed rainbow tables, a more advanced intermediary keying algorithm was implimented. The user supplied password string is appended to a 64 bit random salt and is passed as an input to the Password-Based Key Derivation Function #2 as described in RSA Labratories Public Key Cryptography Standards (PKCS) #5 and in the Internet Engineering Task Force (IETF) RFC 2898. The hash algoritm used is SHA256 and the key is iterated 10,000 times prior to being passed to the cipher algorithm. The result of this operation is 256 bits of session dependent key material.
The PBKDF2/RFC2898 keying algorithm returns 256 bits of iteravely hashed key data. The AES algoritm is used keyed with all 256 bits of key data in it's 256 bit mode. (AES256)
The AES algorithm is operated in the Cipher Block Chaining (CBC) mode with a random one block Initilazation Vector (IV) and PKCS #7 block padding. IV and cipher block sizes are both 256 bits.
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