From the course: Cisco Network Security: Core Security Concepts

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Symmetric encryption

Symmetric encryption - Cisco Tutorial

From the course: Cisco Network Security: Core Security Concepts

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Symmetric encryption

- [Instructor] Symmetric or conventional encryption uses a single shared key to encrypt and decrypt data, and provides fast, efficient encryption. Both parties must have the same key. Symmetric encryption has five ingredients. Plaintext, the encryption algorithm, a shared secret key, ciphertext, and the decryption algorithm which is simply the encryption algorithm run in reverse. Let's step through the process. Alice needs to send Bob a secure message. We start with Alice sending a secret message to Bob. And this is the plaintext input. We add the encryption algorithm and the shared secret key, it becomes ciphertext and it is sent to Bob. Bob uses the same shared secret key, and the decryption algorithm, which is the encrypting algorithm run in reverse. And now the secret message to Bob is the plaintext output. Where did this all begin? Let's look at a little history. In 1973, NIST issued a public request for an encryption algorithm. The algorithm had to meet several criteria. It had…

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