History
From a certificate on the wall to proof on request, in fifty years.
In 1985 a system was trusted because experts had examined it once. Today a machine is expected to prove its state to a stranger, on request. This is how the field got from one to the other.
James Anderson's planning study for the US Air Force describes a small, tamper-proof mechanism that checks every access. The idea that security should rest on a small core starts here. Source
The US Department of Defense publishes its Trusted Computer System Evaluation Criteria. It defines the trusted computing base and grades systems from D to A1. Trust comes from evaluation: experts examine a system once and certify it. There is no way for the system to prove anything to a remote party. Source
Arbaugh, Farber and Smith describe a bootstrap architecture in which each layer checks the next before starting it. The chain of trust becomes a design pattern. Source
Compaq, HP, IBM, Intel and Microsoft form the Trusted Computing Platform Alliance, later the Trusted Computing Group. Its Trusted Platform Module gives ordinary computers a chip that records what booted and signs a report about it. Remote attestation enters commodity hardware. Source
IBM researchers extend measurement from boot into the running Linux system. In the same year, Direct Anonymous Attestation shows how a device can prove it is genuine without revealing which device it is, and property-based attestation is proposed as an answer to brittle hashes. Source
Arm adds a secure world that runs beside the normal operating system, on the same processor. It ships in billions of phones. TrustZone was built for manufacturers. They decide what runs in the secure world. They use it to keep control of the hardware they make: boot keys, payments and media rights. For years it offered little attestation to anyone outside. Android key attestation and Arm's PSA tokens later opened that door.
Intel and AMD add late launch, which restarts the chain of trust after boot and drops the firmware and bootloader from it. Research systems show very small pieces of code running in isolation, with attestation.
Intel describes and ships SGX: protected regions inside a process, with attestation built into the processor. AMD follows with encrypted virtual machines. Attestation moves from the boot chain to the application. Source
The Confidential Computing Consortium forms. The IETF starts its attestation working group. AMD adds integrity protection with SEV-SNP, Intel announces TDX and Arm announces CCA. Whole virtual machines can now be attested. Source
Apple builds its private AI cloud on published measurements that researchers can check. The Entity Attestation Token becomes an RFC. Low-cost attacks on server memory show that a valid quote does not prove who can touch the machine. Source
Formal analysis finds relay attacks on attestation inside the TLS handshake. The EU's Cyber Resilience Act starts to apply, and EU identity wallets, built on wallet and key attestation, fall due. Law and research arrive at the same point: proof has to be repeated. Source
Checked 12 November 2026. Found a wrong date? [email protected]
The founding papers are on the reading list. To see what a trusted computing base contains today, use the TCB definition tool.
Each step moved proof closer to the present moment. First evaluation before sale. Then measurement at boot. Then attestation at launch of an application. The next step is proof that is repeated for the whole life of a product. That step is re-attestation, and it is why this site exists.
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Next fixed date: EU Digital Identity Wallets are due in every member state on 24 December 2026, 42 days from now.