A half-inch square black chip soldered to a green circuit board, its white label reading Mykotronx, MYK78T, 22422, 288885, surrounded by ordinary logic chips. — Exhibition billMykotronx MYK-78T — the Clipper chip — installed on the main board of an AT&T TSD-3600E telephone. Photograph by Matt Blaze, CC BY-NC-ND 2.0. The only picture of the object was taken by the cryptographer who broke it.

Special Exhibition · Hall of the Withdrawn Part

The Won Argument

Tamper-resistant ASIC, NSA silicon, and one public victory

Dimensions: Half an inch square; thirty-three years in service
Date: Manufactured 1993. Declared defunct 1996. Still shipping 2026.

The Vitrine — Evidence

Quotation01
Microsoft Learn — Pluton as TPM, 16 September 2026
“Beginning with 2026 silicon, Microsoft Pluton no longer serves as the TPM on AMD and Qualcomm platforms. On these platforms, as well as on Intel, TPM 2.0 functionality is instead delivered through the vendor’s firmware TPM (fTPM) or a discrete TPM.” … “This change affects only Pluton’s TPM functionality. The Pluton security processor will continue to be present and supported on existing and future Windows devices.”
Primary source ↗
Quotation02
Who writes the firmware, and who delivers it
“Pluton is integrated within the SoC subsystem, and provides a flexible platform for running firmware that implements end-to-end security functionality authored and maintained by Microsoft.” … “delivering firmware updates directly from Windows Update.” … Manufacturers may use another TPM “while keeping Pluton available to the system for use cases beyond the TPM.”
Primary source ↗
Figure03
The field that carried the key
128 bits: a 32-bit chip serial number, the 80-bit session key encrypted under the device’s unit key, and a 16-bit checksum — the whole structure sealed with a “family key” shared by every interoperable device ever made.
Primary source ↗
Quotation04
Blaze, Protocol Failure in the Escrowed Encryption Standard, 20 August 1994
“The LEAF checksum is, in fact, 16 bits. A brute-force search of the LEAF space for a valid LEAF requires about 2^16 operations.” The paper evaluates “the publicly released aspects of the EES protocols” — the escrow failed at the one layer anyone outside the agency was permitted to read.
Primary source ↗
Primary document05
Blaze — Key Escrow from a Safe Distance: Looking Back at the Clipper Chip (ACSAC, 2011)
Primary source ↗
Reference06
The same transfer, in software — LifeLog § 05d, The Consent Screen
Eleven permissions listed where one unreadable line used to sit: the access did not change, only whether anyone could read it.
Primary source ↗

Wall LabelAs authorized

In April 1993 the United States government proposed that every secure telephone carry a chip of its own design. The Clipper chip encrypted the call and, in the same operation, transmitted a Law Enforcement Access Field containing the session key, recoverable by the state through two escrow agencies.

The public refused. Cryptographers took the protocol apart, industry declined to buy it, Congress lost its nerve, and by 1996 the programme was finished.

The museum presents this piece as the founding victory of the digital civil-liberties era: the one time a population was told in advance what the machine would do, read the specification, and said no.

Conservation Notes

01
Placement
The keyholder was moved out of the name. “Law Enforcement Access Field” is a phrase a citizen can object to. “Security processor” is not.
02
Layering
“Escrow” overpainted as “root of trust”; “backdoor” as “attestation”; “the state can recover your key” as “keys cannot be easily extracted.”
03
Integration
Clipper had to be bought, and could therefore be refused. Its successor is fabricated into the processor and arrives with the machine.

4 lines off this wall. Take one to the street.