Cryptography

Annotations:

• A pair of keys are used -> They are also known as Public key cryptography because there are a public key and a private key, 2 for each party.

Attachments:

• Certificates

1. Diffie-Hellman
   1. ECDH
2. RSA
3. DSA
   1. ECDSA

Annotations:

• These algorithms use 1 symmetric key both for encryption and decryption.  Are particularly suitable for large amount of data.

1. Block Algorithms

   Annotations:

   • They split data in blocks of equal size, then process 1 block at time.
   1. DES
      1. 3DES (EEE or EDE)
   2. IDEA
   3. RC2
   4. RC5
   5. AES
   6. Operation modes

      Annotations:

      • These are applied in case the data dimension is different from the basic block dimension
      1. data > basic block
         1. ECB
         2. CBC
         3. IGE
         4. CTS

            Annotations:

            • This not uses padding and does not send more that than necessary
         5. Padding
      2. data < basic block
         1. CFB
         2. OFB
         3. CTR
2. Stream Algorithms

   Annotations:

   • Able to work on stream of data, 1 bit or byte at time.
   1. RC4
   2. SEAL
   3. Key stream
      1. pseudo-random key
      2. one-time pad