Hashing Questions Medium
The role of a hash function in digital signatures is to ensure the integrity and authenticity of the message being signed.
When creating a digital signature, the hash function takes the input message and produces a fixed-size hash value or message digest. This hash value is unique to the input message, meaning even a small change in the message will result in a completely different hash value.
The hash value is then encrypted using the private key of the signer, creating the digital signature. This signature is attached to the original message and can be verified by anyone using the corresponding public key.
During the verification process, the recipient of the message recalculates the hash value of the received message using the same hash function. They then decrypt the digital signature using the public key of the signer. If the recalculated hash value matches the decrypted signature, it confirms that the message has not been tampered with and was indeed signed by the claimed sender.
In summary, the hash function plays a crucial role in digital signatures by providing a secure and efficient way to verify the integrity and authenticity of a message.