Encryption basics
General principles of modern encryption
- The same key is used for encryption and decryption.
- Adapted to fast processing of large quantity of data.
- Small key length (128 - 256 bits).
- Algorithms : 3DES, AES, DES, RC4.
- A public key is used for encryption, a private key is used for decryption.
- Adapted to slow processing of small quantity of data.
- Large key length (1024 - 4096 bits).
- Algorithms : Diffie-Hellman, ECC, ElGamal, DSA, RSA.
- The creation of a key pair involves very large prime numbers and modular arithmetic.
- When multiplying very large prime numbers together, their product is impossible to factor without knowledge of the original numbers.
- It’s not magic, it just happens to be the way the maths work with prime numbers.
- In order to crack the encryption, one would have to be able to factor the product of those large prime numbers, which current computing power does not allow.