NIST announces the release of Special Publication (SP) 800-67, Revision 2, Recommendation for the Triple Data Encryption Algorithm (TDEA) Block Cipher. This publication specifies the Triple Data Encryption Algorithm (TDEA), including its primary component cryptographic engine, the Data Encryption Algorithm (DEA). TDEA operations are performed using a "bundle" of three keys and produce 64-bit blocks as output. The security of TDEA is affected by the number of blocks processed with one key bundle. In response to known security weaknesses, this revision reduces the maximum amount of plaintext allowed to be encrypted using a single TDEA 3-key bundle from 2³² to 2²⁰ blocks. An announcement to explain this change is available here.