Preliminary knowledge

To effectively use our library, we assume some basic knowledge of public key cryptography as well as Rust.

Cryptography and math

  • Plaintext vs. ciphertext: Plaintext refers to unencrypted data (i.e. data in the clear) whereas ciphertext refers to encrypted data.
  • Public key vs. private key: In public key cryptography, there are two types of keys. The public key (aka the encryption key) can be shared with others. Using the public key, people can send encrypted messages. The private key (aka the decryption key) should not be shared. Whoever holds the private key can decrypt the messages addressed to them (which are encrypted under the corresponding public key). Usually, each person has their own public/private key pair.
  • "Homomorphic": We use this term to denote computations performed directly on encrypted data. For example, if we say "homomorphic addition," we are referring to addition of two ciphertexts.
  • Modulus: We use this term in the context of discussing modular arithmetic (aka clock arithmetic). Under modular arithmetic, values "wrap around" when they exceed the modulus. In the example 7 mod 4 = 3, 4 is the modulus.

Rust and programming