The Crovia Seal: A Cryptographic Receipt Format for AI-Generated Output Provenance

This document specifies the Crovia Seal v1, a compact, tamper-evident JSON receipt that may be attached to any output produced by an AI generator (large language model, image model, audio model, or composite system) to record its provenance in a cryptographically verifiable form. A Crovia Seal binds an issuer's identity to the SHA-256 digests of an input/output pair, the identity and parameters of the generator, an emission timestamp, and a per-issuer hash chain, under an Ed25519 signature computed over a strict canonicalization (CSC-1) of the receipt with explicit domain separation. Optional fields permit transparency-log inclusion proofs and witness co- signatures. The Seal is designed for offline verification and for inclusion in third-party transparency logs and standards-based revocation infrastructure.