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.

12. Code Signing

Code signing is used by software manufacturers as a way to ensure that the code is legitimate. This means then when the OS is updated on a computer, the digital signature of the update is checked to ensure that the update is from the manufacturer. Another popular example of code signing is the downloading of iPhone apps from the App store.