What is Cryptographic Signature
A cryptographic signature is a mathematical technique used to validate the authenticity and integrity of your credential. Signatures are based on public key cryptography, also known as asymmetric cryptography, which uses a pair of mutually authenticating keys – a public key and a private key – to encrypt and decrypt a message.
RSA, or Rivest-Shamir-Adleman, is the most popular asymmetric cryptographic algorithm in use today. It is primarily used for encrypting messages but can also be used for performing digital signatures over a message. Let us understand how RSA can be used for performing digital signatures step-by-step. Assume that there is a sender (A) and a receiver (B). A wants to send a message (M) to B along with the digital signature (DS) calculated over the message. First, A generates a pair of keys using RSA - a public key and a private key. The public key can be shared with anyone, but the private key must be kept secret.