1. Module 5 Desktop/Laptop Security Module 5

6. Encryption

7. EFS

9. Decryption

10. Decrypting

13. Conventional Encryption Hello Hello KEY KEY $*(*&^YGCI&^*&Y

15. Asymmetric Encryption

20. Hard Disk Encryption

22. Public-Key Cryptography - Encryption

23. Public-Key Cryptography - Authentication

28. Combining Public Key & Symmetric Key Encryption Plaintext Plaintext Hi Bob Alice Hi Bob Alice X2c67afGkz78 Session Key xaF4m 78dKm Alice Bob Ciphertext Hi Bob Alice Session Key Encrypt 1. Message B's private key Decrypt 3. Session Key Decrypt 4. Message B's public key Encrypt 2. Session Key

29. Digital Signature with a Message Digest Plaintext Plaintext Alice Bob Hi Bob Alice Hi Bob Alice Hi Bob Alice Encrypted MD (“signature”) Unencrypted message =? A's public key Decrypt 1764890238 3. Decrypt Alice’s Message Digest 1764890238 MD 4. Compute the MD MD 1764890238 Digest 1. Message Digest A’s private key 2. Encrypt the MD