In 1993, NIST proposed a voluntary federal standard for escrowed encryption to enhance telephone communication security while addressing law enforcement needs. The standard, which included the SKIPJACK algorithm and Law Enforcement Access Field (LEAF) method, focused on voice, fax, and low-speed data encryption. Implementation details were classified. This proposal was part of a broader voluntary key escrow encryption program announced that year, with NIST responsible for developing such security standards under the Computer Security Act of 1987.
Keywords: SKIPJACK, LEAF, NIST