Digital signature
A digital signature is an unforgeable stamp on an electronic message. Every digital signature is tied to a public key. The public key can be linked to identifying information about the author who owns the public key and produces the signature. Producing this signature requires knowledge of a private key corresponding to the public key. It is impossible to guess the private key corresponding to the public key. Additionally, it is impossible to forge a signature on any message which wasn’t previously signed. Digital signatures provide integrity and non-repudiation for electronic statements, such as a financial transaction issued by the owner of an asset or a credential that a government authority issues to a business.