There are different types of encryption techniques are being used to ensure the privacy of data transmitted over internet. Digital Signature is a mathematical scheme which ensures the privacy of conversation, integrity of data, authenticity of digital message/sender and non-repudiation of sender. Digital Signature is embedded in some hardware device or also exits as a file on a storage device. Digital Signature are signed by third party some certifying authority. This paper describe the different key factor of digital signature with the working of digital signature, through various methods and procedures involved in signing the data or message by using digital signature. It introduces algorithms used in digital signatures.