Symmetric Key Algorithms

You already learned about symmetric key ciphers and the major issue with symmetric keys. Read the section in this article on symmetric key encryptions to learn more about the advantages and disadvantages of symmetric keys. There is more information about symmetric key ciphers in this article that will be covered in more detail later in this unit, but this article will give you a preview of 3DES, IDEA, and AES ciphers. View the flashcard tool as well to better understand and to learn the terms used in cryptography such as plaintext, ciphertext, key, encryption, decryption, countermeasure, symmetric key encryption, and block cipher.

11. Digital Signature

A digital signature is a hash value encrypted with the sender's private key. The receiver can decrypt the hash value with the sender's public key providing authentication, non-repudiation, and integrity. The receiver is assured that the message had indeed come from the sender. Read How digital signatures work for more information on the components involved.

Since the sender of data is provided with proof of delivery and the recipient is assured of the sender's identity, digital signatures provide non-repudiation.