NTRU Crypt

This is a minimal pure Rust implementation of the NTRU Public key cryptosystem, done as part of a project for a cryptography class. It implements the NTRU system to the specification of the original (1998) paper, including the levels of security recommended by that paper. Several enhancements to the algorithm have been made since, as well as hightened levels of security to combat the increase in computational power available to attackers. Do not trust this software to securely encrypt your data to a modern, reasonable standard. Do trust this software to encrypt your data such that an attacker in 1998 could not feasably retrieve it.

This implementation is not published on crates.io as it is strictly inferior to other pure rust implementations in terms of scope and speed, as it is only a proof of concept demonstration. To install it to your system globally, you will need rust to be installed (see https://https://www.rust-lang.org/tools/install). This can then be installed by

git clone https://github.com/joeoneil/ntru_crypt
cd ntru_crypt
cargo install --path .

Usage

ntru_crypt provides 3 subcommands, keygen, encrypt, and decrypt, which do exactly what they say. That is, generate keys, encrypt files, and decrypt files.

Key generation

keygen takes two arguments -s n where n is the desired security level (between 0 and 3), as well as the name -f [name] which defaults to 'id_ntru'. Note that while this has a similarity in name to ssh-keygen, these keys cannot be used as ssh keys, and the similarity ends at the name.

ntru_crypt -s 2 --filename l2_key

Will make a key pair l2_key containing the private key and l2_key.pub contianing the public key.

Encryption / Decryption

encrypt and decrypt take similar arguments which are as follows:

-if, --input-file the input file (plaintext or ciphertext)

-kf, --key-file the key (public or private) to use

-ifmt, --input-format the format of the input data (decryption only)

-of, --output-format the format of the output data

Encryption and decryption support ciphertexts in base64, base64 web, and binary formats. Decryption can also decode to base64 data, although I'm not sure why you would want that (but it is an option). Setting the output format to 'Text' for decryption will validate that the output data is valid UTF-8, but will not modify the resultant data. Decrypting a binary file with output format 'Text' will (likely) fail if the binary is not valid UTF-8.

More information about subcommands and their usage can also be found by ntru_crypt --help or ntru_crypt [subcommand] --help.