Conventional encryption principles

1. Examples of public-key cryptosystem

1.1. Elgamal

1.2. RSA

2. Public key

2.1. Application for public-key cryptosystem

2.1.1. Encryption/decryption

2.1.2. Digital signature

2.1.3. Key exchange

3. ‏conventional encryption algorithm

3.1. Encryption ingredients

3.1.1. Plaintext

3.1.2. Encryption algorithm

3.1.3. Secret key

3.1.4. Ciphertext

3.1.5. Decryption algorithm

3.2. Source use of symmetric encryption

3.2.1. A strong encryption algorihm

3.2.2. A secret key known only to sender/reciver

4. Cryptographic attack methoods

4.1. Plaintext based attacks

4.1.1. Known plaintext

4.1.2. Chosen plaintext

4.1.3. Adaptive chosen plaintext

4.2. Ciphertext based attacks

4.2.1. Ciphertext only

4.2.2. Chosen ciphertext

4.2.3. Adaptive chose ciphertext

5. Man in the middle attack

5.1. make it seem that two computers are communication with each other.