Cryptography based on industry-tested and accepted algorithms, along with key lengths that provide a minimum of 112-bits of effective key strength and proper key-management practices. Cryptography is a method to protect data and includes both encryption (which is reversible) and hashing (which is “one way”; that is, not reversible). See Hashing.
At the time of publication, examples of industry-tested and accepted standards and algorithms include AES (128 bits and higher), TDES/TDEA (triple-length keys), RSA (2048 bits and higher), ECC (224 bits and higher), and DSA/D-H (2048/224 bits and higher). See the current version of NIST Special Publication 800-57 Part 1 (http://csrc.nist.gov/publications/) for more guidance on cryptographic key strengths and algorithms.
Note: The above examples are appropriate for persistent storage of cardholder data. The minimum cryptography requirements for transaction-based operations, as defined in PCI PIN and PTS, are more flexible as there are additional controls in place to reduce the level of exposure.
It is recommended that all new implementations use a minimum of 128-bits of effective key strength.
