What is a digital signature?
A digital signature functions for electronic documents like a handwritten signature does for printed documents. The signature is an unforgeable piece of data that asserts that a named person wrote or otherwise agreed to the document to which the signature is attached. A digital signature actually provides a greater degree of security than a handwritten signature. The recipient of a digitally signed message can verify both that the message originated from the person whose signature is attached and that the message has not been altered either intentionally or accidentally since it was signed. Furthermore, secure digital signatures cannot be repudiated; the signer of a document cannot later disown it by claiming the signature was forged. In other words, digital signatures enable “authentication” of digital messages, assuring the recipient of a digital message of both the identity of the sender and the integrity of the message.
A digital signature mimics in the virtual environment the function of a hand-written signature in printed documents. Information related to a unique user is encrypted in a private key that is appended to any message sent by this user. It authenticates the identity of the user and guarantees the integrity of the message.
Digital Signatures are based on Public Key Technology that uses asymmetric cryptography. Each person’s identity is related to a key pair – a private key and a public key. These keys are nothing but mathematical codes. During the signing, once the user initiates the process, a mathematical code is generated with the help of an algorithm and, the digital contents. The code generated, known as the ‘message digest’, is unique for each process and content. The individual’s private key is now used to encrypt this code.
A digital signature functions for electronic documents like a handwritten signature does for printed documents. The signature is a non-forgeable piece of data that asserts that a named person wrote or otherwise agreed to the document to which the signature is attached. A digital signature actually provides a greater degree of security than a handwritten signature. The recipient of a digitally signed message can verify both that the message originated from the person whose signature is attached and that the message has not been altered either intentionally or accidentally since it was signed. Furthermore, secure digital signatures cannot be repudiated; the signer of a document cannot later disown it by claiming the signature was forged. In other words, digital signatures enable “authentication” of digital messages, assuring the recipient of a digital message of both the identity of the sender and the integrity of the message.
Not to be confused with a digitized signature (a scan of a hand-written signature), a digital signature can be used with either encrypted or unencrypted messages to confirm the sender’s identity and ensure the recipient that the message content has not been changed in transmission. Digital signatures incorporate the characteristics of hand-written signatures in that they can only be generated by the signer, are verifiable, and cannot easily be imitated or repudiated.
