diff --git a/README.md b/README.md index e26178f..25ff3a3 100644 --- a/README.md +++ b/README.md @@ -1,6 +1,7 @@ ### Tiny ECDH in C This is a small and portable implementation of the [Elliptic-Curve Diffie-Hellman key agreement algorithm](https://en.wikipedia.org/wiki/Elliptic-curve_Diffie%E2%80%93Hellman) written in C. + It is especially usable for generating ephemeral session keys and encrypting communications symmetrically after agreement. You can choose between 10 standard NIST curves of different sizes. 5 "pseudo-random" curves and 5 Koblitz curves providing from ~80 to ~256 bits symmetrically equivalent security. See [ecdh.h](https://github.com/kokke/tiny-ECDH-c/blob/master/ecdh.h) for clarification. @@ -11,7 +12,8 @@ The API is very simple and looks like this (I am using C99 ``-style an /* NOTE: assumes private is filled with random data before calling */ int ecdh_generate_keys(uint8_t* public, uint8_t* private); -int ecdh_shared_secret(const uint8_t* private, const uint8_t* other_pub, uint8_t* output); +/* input: own private key + other party's public key, output: shared secret */ +int ecdh_shared_secret(const uint8_t* private, const uint8_t* others_pub, uint8_t* output); ``` You need to provide random data for the private key yourself, for the key generation process.