Digital Signature

A digital signature is a mathematical technique used to validate the authenticity and integrity of a message, software or digital document. It's the digital equivalent of a handwritten signature or stamped seal, but it offers far more inherent security.
A digital signature is intended to solve the problem of tampering and impersonation in digital communications.
Digital signatures can provide evidence of origin, identity and status of electronic documents, transactions or digital messages. Signers can also use them to acknowledge informed consent.

Types of Digital Signature
1) Direct Digital Signature
Involves only the communicating parties, i.e., source and destination

2) Arbitrated Digital Signature
Involves a third party (an arbiter who will solve the dispute between the sender and the receiver) along with the source and destination