Digital Signatures
Digital signatures are a category of algorithms based on public key cryptography. They are used for verifying the authenticity and integrity of a message. To create a digital signature, the message is passed through a hashing algorithm. The resulting hashed value is then encrypted with the sender’s private key. Upon receiving the message, the recipient decrypts the encrypted sum and then recalculates the expected message hash using the sender’s public key. The values must match to prove the validity of the message and verify that it was sent by the party believed to have sent it. Digital signatures work because only that party has access to the private key. Let’s break this process out step-by-step to help detail the operation:
- Bob produces a message digest by passing a message through a hashing algorithm.
- The message digest is then encrypted using Bob’s private key.
- The message is forwarded to the recipient, Alice.
- Alice creates a message...