What is a Cryptographic Stamp Identifier (CSID)?
A CSID is technically a cryptographic certificate, which is a credential that allows for authenticated signing and encryption of communication. The certificate is also known as a public key certificate or an identity certificate. It is an electronic document used as proof of ownership of a public key. A CSID is used to uniquely identify an Invoice Generation Solution Unit in possession of a Taxpayer for the purpose of stamping (technically cryptographically signing) Simplified Invoices (B2C) and for accessing the Reporting and Clearance APIs.