attestation
also: measured boot, remote attestation, TPM attestation
A cryptographic proof or verification that confirms the authenticity, integrity, and trustworthiness of system components, firmware, or software at runtime or boot time.
Attestation is a security mechanism that provides cryptographic evidence that a system or its components have not been tampered with or compromised. It uses hardware-based or firmware-based measurements and signatures to prove that code executed is genuine and unmodified.
Common forms include measured boot attestation, where the bootloader and kernel are measured (hashed) before execution, with results stored in a Trusted Platform Module (TPM). Remote attestation allows a client system to prove its state to a remote server, essential for systems requiring high security like enterprise infrastructure or cloud instances.
For example, a server using TPM 2.0 can attest to its secure boot status by providing a digitally signed report of boot measurements. A verifier can then confirm the system booted with legitimate, unmodified firmware.