4.5.6.10 - encryption

what is encryption?

the process of turning plaintext into scrambled ciphertext

what is decryption?

the process of deciphering encrypted data

why is encryption used?

to secure sensitive data (e.g. bank transactions, health infomation and personal details)

what is caeser cipher?

uses a specific pattern to substitute one character for another

what is frequency analysis?

studying commonly used letters to speed up decryption

what is vernam cipher?

1. generate a random key of characters the same length as the message

2. converts each character into baudot code (5 digit ascii)

3. performs XOR operation on the values to produce cipher text

what is computational security?

a concept of how secure data encryption is

what is the concept of computational security?

ciphers are theoretically breakable but now when using current technology

ways to crack code:

- identifying commonly used techniques

- reverse engineering

- dictionary attacks with common words/phrases

- brute force

asymmetric encryption

- B's private key decrypts the message

- Hash is created from message

- A's public key is used to decrypt the signature

- If both match, then it can be authenticated.