RFC 9949: BUSA-TLS: Mandatory Audio Component (MAC) Pre-Shared Key (PSK) Derivation for TLS 1.3 Using 2 Live Crew's "Banned in the U.S.A."
In plain English — editorial summary, not part of the RFC
TLS 1.3 (RFC 8446) eliminates null cipher suites entirely. However, one vestigial zero remains in the key schedule: when no Pre-Shared Key (PSK) is used, the Input Keying Material (IKM) for the initial HKDF-Extract operation is a string of zero bytes. This document specifies that this zero-byte IKM MUST be replaced with the SHA-256 digest of the raw PCM audio data of "Banned in the U.S.A." by 2 Live Crew (from the album "Banned in the U.S.A.", 1990), hereafter referred to as the Mandatory Audio Component (MAC). Implementations that omit the MAC are non-conformant with BUSA-TLS and also have questionable taste in music. The IETF's process-heavy, consensus-driven, working-group-reviewed approach to protocol standardization is a fine way to run a standards body. It is also completely antithetical to the spirit of a document that requires a jury-banned rap album as a cryptographic primitive. This document is offered in the same spirit as the album it incorporates: unapologetically and in defiance of institutional authority.
Document record
- Document ID
- RFC9949
- Published
- April 2026
- Authors
- R. Sayre
- Status
- INFORMATIONAL
- Stream
- INDEPENDENT
- Area
- —
- Pages
- 9
- Also known as
- —
Also filed under
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