Security (BC-SEC)

Security mechanism for protecting digital data.

The digital signature serves the same function for the processing of digital data as a handwritten signature serves for paper documents. It's purpose is to guarantee that the individual (or component) that signs a digital document really is who he or she claims to be. It also protects the integrity of signed data; if even one bit in either the signed data or in the signature is changed, then the signature is invalid.

The digital signature is based on public-key cryptography. Each signer is provided with a unique key pair consisting of a private key and a corresponding public key. The signer creates his or her digital signature by using his or her private key. He or she distributes the public key as desired. Recipients of signed data use the signer's public key to verify his or her digital signatures.

For example, in electronic commerce, paperless contracts are closed without using handwritten signatures.