The document discusses symmetric encryption principles and algorithms. It covers the basic components of conventional encryption including plain text, encryption algorithms, keys, cipher text and decryption algorithms. It then describes common symmetric encryption algorithms like the Data Encryption Standard (DES) and the Advanced Encryption Standard (AES) which replaced DES. The document also discusses concepts like cryptanalysis, key distribution and the location of encryption devices.

1. Chapter 2 Symmetric Encryption and Message Confidentiality

6. Conventional Encryption Principles

11. Types of Attacks

13. Average time required for exhaustive key search 2.15 milliseconds 232 = 4.3 x 109 32 5.9 x 1030 years 2168 = 3.7 x 1050 168 5.4 x 1018 years 2128 = 3.4 x 1038 128 10 hours 256 = 7.2 x 1016 56 Time required at 106 Decryption/µs Number of Alternative Keys Key Size (bits)

21. Time to break a code (106 decryptions/µs)

23. Triple DEA

29. AES Parameters

30. AES Encryption & Decryption

31. AES Data Structures

32. AES Encryption Round

34. Substitute Bytes

35. S-Box

36. Inverse S-Box

37. Substitution of Bytes

39. Shift Rows

40. Shifting of rows

42. Mix Columns

44. Add Round Key

46. Stream Cipher Diagram

47. Stream Ciphers

48. Stream Ciphers