NIST FIPS 185

Citation
NIST, Escrowed Encryption Standard (EES) (Feb. 9, 1994) (full-text).

Overview
This tandard specifies use of a symmetric-key encryption (and decryption) algorithm (SKIPJACK) and a Law Enforcement Access Field (LEAF) creation method (one part of a key escrow system) which provides for decryption of encrypted telecommunications when interception of the telecommunications is lawfully authorized. Both the SKIPJACK algorithm and the LEAF creation method are to be implemented in electronic devices (e.g., very large scale integration chips). The devices may be incorporated in security equipment used to encrypt (and decrypt) sensitive unclassified telecommunications data. Decryption of lawfully intercepted telecommunications may be achieved through the acquisition and use of the LEAF, the decryption algorithm and the two escrowed key components.