Digital Signature

Digital Signature

Digital signature is a mathematical technique used to validate the authenticity and integrity of a message, software or digital documents. A valid digital signature gives a recipient reason to believe that the message was created by a known sender , that the sender cannot deny having sent the message and that the message was not altered in integrity. Digital signature are like electronic fingerprints in the form of coded message which uses standard accepted format called Public Key Infrastructure(PKI) ,to provide highest levels of security and universal acceptance.

Digital signature are based on public key cryptography. Using public key algorithm such as RSA, one can generate two keys that are linked mathematically : One private key and one public. When the data are being send form any platform then it creates s one way hash of the electronic data .Then private key is used to encrypt the hash along with the data and send to the receiver where receiver uses the public key to decrypt the hash along with the information. Since encrypting the whole information that is being send by the sender takes more time ,only the hash code is encrypted as it can be converted into fixed length value which will be more convenient and faster than signing. Further there will be more efficiency, compatibility and data integrity . The value of hash is unique to the hashed data ,even changing or deleting single character of data ,results in different value.