ring-LWE

Implmentation of lattice-based encryption method ring-LWE in pure Rust.

Description

This provides the basic PKE (keygen, encryption, and decryption) operations for the ring learning-with-errors scheme.

Disclaimer

This is not secure. It is not written in constant-time nor resistant to other side-channel attacks. This is intended for educational use and not for real-world applications.

Build and test

In the src directory,

cargo build

To build the binary.

cargo test

• Performs keygen/encrypt/decrypt for a test message.
• Checks homomorphic addition and multiplcation hold for small values.

Keygen

Note: Parameters optional.

• cargo run -- keygen --n 512 --q 12289 --t 2

where n is the polynomial degree, q is the ciphertext modulus, t is the plaintext modulus.

If ommitted, the default parameters will be used.

cargo run -- keygen

This will generate a public/secret keypair printed to the console.

To save the key files to public.key and secret.key, use the --save-keys flag:

cargo run -- keygen --save-keys

Encryption

To encrypt a message using the public key using command line arguments:

cargo run -- encrypt <public_key> <message>

To encrypt a message using a public key file:

cargo run -- encrypt --pubkey-file public.key "Hello, world!"

To encrypt a message and save the ciphertext to file:

cargo run -- encrypt --pubkey-file public.key 'Hello, world!' --ciphertext-file ciphertext.txt

Decryption

To decrypt an encrypted message using the secret key using command line arguments:

cargo run -- decrypt <secret_key> <ciphertext>

To decrypt an encrypted message using the secret key file:

cargo run -- decrypt --secret-file secret.key <ciphertext> --n 512 --q 12289 --t 2

To decrypt an encrypted message from a file ciphertext.txt:

cargo run -- decrypt --secret-file secret.key --ciphertext-file ciphertext.txt

Benchmarks: