Confidentiality

Confidentiality

1. Asymmetric Encryption or Public Key (new)

   • Uses 2 keys
   • Digital Signatures
     • DSA
   • Algorithms
     • RSA
       • Most used
     • key exchange or agreement
       • Key Management
     • ECC
       • New Faster

2. Symmetric encryption or Single Key (old, popular)

   • Attacks: Cryptanalysis Brute-force
   • Block encryption algorithms or Block Ciphers
     • Take in a block of text Apply a key Spit out encrypted block ECB mode Can reuse key
     • Advanced Encryption Standard (AES)
       • 128 bit block bit key
     • Data Encryption Standard (DES) or DEAlgorithm
       • Very well studied No fatal flaw found 2^56 possible keys, too little slow
       • Triple DES or 3DES
         • Repeating DES 3 times 112-168 bits keys no cryptoanalysis 3xslower
   • Secure hash function or One Way Hash Function
     • Message or data authentication
     • Secure Hash Function Algorithms SHA
   • Stream Ciphers
     • Faster used for stream of data

3. Random Numbers