An attestation key is a cryptographic key stored within secure hardware, such as a Trusted Platform Module (TPM) or secure enclave. Its main purpose is to prove that the device is genuine and has not been tampered with. When a system or application requests proof of authenticity, the attestation key signs specific data, allowing external parties to verify the device’s integrity and trustworthiness. This process is essential in trusted computing environments, helping to ensure that only authorized and uncompromised devices can access sensitive data or services. The attestation key itself is kept secret and protected by the hardware, making it difficult for attackers to forge or misuse.