Dignature is a digital signature solution developed by Matter-ID that combines Public Key Infrastructure (PKI) with biometric verification for document signing and authentication. The product uses facial recognition and secret PIN codes to create a dual-factor authentication process that ties digital transactions to the physical identity of the signer. The solution is built on the Secure Digital Identity Suite platform, which enables users to create digital twins of biometric documents. It employs cryptographic techniques to protect digital identities and stores them as cryptographically independent components to reduce the risk of identity theft. Dignature provides authentication, integrity verification, and non-repudiation for digitally signed documents. The platform supports flexible cryptographic scheme management, allowing for integration of new cryptographic schemes and retirement of outdated ones while maintaining operational efficiency. The product includes Zero-Knowledge Identity Technology that enables users to create sub-identities with minimal information disclosure while maintaining verifiable authenticity. This allows for privacy-preserving authentication where users can control the amount of information they share during verification processes. The solution is designed to provide consistent security throughout a document's lifecycle, from creation to expiration, and aims to protect against identity forgery and unauthorized access through its combination of biometric and cryptographic controls.