Sign Protocol is an omni-chain attestation protocol, enabling users to freely attest and verify any information on-chain. Sign Protocol offers a suite of tools, infrastructure, and standards to create a future where all claims and assertions on the web and the world around us are driven by verifiable attestations. It does this by leveraging modern technologies, such as decentralized blockchains and data storage solutions, along with novel techniques such as the use of zero-knowledge cryptography and digital signatures.