BUSA-TLS: Mandatory Audio Component Pre-Shared Key Derivation for TLS 1.3 Using 2 Live Crew's "Banned in the U.S.A."
RFC 9949, “BUSA-TLS: Mandatory Audio Component Pre-Shared Key Derivation for TLS 1.3 Using 2 Live Crew's "Banned in the U.S.A."”, is an Informational document published in April 2026 by R. Sayre. The canonical text is published by the RFC Editor.
Abstract
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.
What “Informational” means
Published for the general information of the community. It does not define an IETF standard and carries no standards-track status.
The canonical text of RFC 9949 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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