Signature activation module (SAM)

Signature Activation Module (SAM): the EN 419 241-2 component that enforces sole control in remote signing before each qualified signature is created.

A Signature Activation Module (SAM) is a security component defined by the CEN EN 419 241-2 standard that enforces sole control of the signature creation data in remote signing systems. Rather than sitting between the authentication layer and the QSCD, the SAM operates either within the same tamper-protected environment as the cryptographic module, or in a separate tamper-protected environment linked to it by a trusted channel; either way, together they form the QSCD, which is typically hosted in an HSM. Before each signature, the user must explicitly approve the operation with an independent factor (PIN, biometric, or out-of-band confirmation); this approval is captured as SAD (Signature Activation Data) and cryptographically linked to the data to be signed (DTBS/R) via the Signature Activation Protocol (SAP) before the private key is used.