APPENDIX B (NORMATIVE) APPROVED CRYPTOGRAPHIC ALGORITHMS AND PROTOCOLS All Cryptographic algorithms recommended in this Appendix B are valid for one year after the date of issue of this manual. The GIAM shall recommend updates or alternatives to this algorithms as and when necessary. These algorithms and protocols are used for encryption, digital signatures, random number generation, key agreement, key transportation, key wrapping, deriving additional keys from a cryptographic key, hash numbers, MAC, etc. Symmetric Key/Private Key: Cryptographic functions that use a symmetric key cipher (sometimes referred to as private key encryption) employing a shared secret key must adopt any of the following specifications. Algorithm Name References Approved Use Required Key Length AES Advanced Encryption Standard block cipher based on the “Rijndael” algorithm [AES] General Data Encryption 256-bit keys TDES /3DES Triple Data Encryption Standard (or Triple DES) block cipher [SP800-67] General Data Encryption three unique 56-bit keys Note: AES SHOULD be used unless this is not technically possible. TDES usage should be limited to systems not supporting AES. Asymmetric Key/Public Key: Cryptographic functions that use asymmetric key ciphers (also known as public key encryption) that employ a pair of cryptographic keys consisting of one public key and one private key must adhere to the following specifications: Algorithm Name References Approved Use Required Key Length RSA “Rivest-Shamir-Adleman” algorithm for publickey cryptography [RSA] Digital Signatures, Transport of encryption 1024-bit keys DSA Digital Signature Algorithm [FIP186-2] Digital Signatures 1024-bit keys Note: 1024 bit keys are to be replaced with 2048 bit keys for RSA and lpl>=2048 bits & lql>=224 bits for DSA by 2013. Use of 1024 bit keys will be discontinued after 2013. NATIONAL INFORMATION ASSURANCE MANUAL 54