IT 223 Lecture Notes - Lecture 4: Non-Repudiation, Plaintext, Dictionary Attack

• School: George Mason University
• Department: Information Technology
• Course: IT 223
• Professor: Thomas Winston

Document Summary

Cryptography - important foundation technology for many information security applications. The transformation of meaningful data into something not meaningful. Cryptanalysis the counterpart to cryptography (the process of defeating cryptographic system) cryptography: the good guys cryptanalysis: the bad guys p10. Key the encryption process is varied by incorporating a data value p13. Encryption and decryption processes algorithms (process) p14. Two type of cryptography: symmetric, asymmetric symmetric: using same key to do inverse and reverse asymmetric: same operation but two different key p17: symmetric: confidentiality, authentication of origin, authentication of integrity asymmetric: confidentiality, authentication of origin, non-repudiation. Two type of decryption: substitution cipher: transposition: product cipher: uses both p34. Brute force attack: (try every possible key value) p47.