Using digital signatures

- [Instructor] A digital signature … provides message authentication … using public key or asymmetric encryption. … This can provide assurance of authentication … with minimal processing. … Let's step through the process … of creating a digital signature. … Alice needs to send Bob a message. … Now here we see Alice on the left hand side … with a public key and a private key. … A hash function is used to create a message digest, … which is a fingerprint of the message. … The message digest in encrypted using Alice's private key, … which then becomes the signature. … The encrypted message digest … is appendant to the message. … The message is then sent to Bob. … Now once it gets to Bob, … Bob takes the message and generates the message digest. … The encrypted message digest … is decrypted using Alice's public key. … And then the two digests are then evaluated. … If they are the same, Alice's signature is verified. … A digital signature can provide sender verification, … but it does not provide confidentiality, …