An architecture and system are provided for flexible, composable attestation systems. Systems built according to this attestation architecture can be composed to accomplish complex attestation scenarios. The system is designed around composable components to permit flexible recombination. A system, method, and computer program product are provided for proving attestations to an appraiser regarding a target system. In an embodiment, an attestation request is sent from an appraiser to a target system, wherein the attestation request includes queries regarding properties of the target system needed by the appraiser to make trust decisions regarding the target system. The attestation request is forwarded from the target system to an attester which collects the requested data. The attester sends an attestation response to the appraiser, wherein the response includes at least information regarding properties of the target system requested by the appraiser in order to make a trust decision regarding the target system.