A public-key cryptography tool for personal use: A real-world implementation of ECC for secure file exchange

A new library of modular arithmetic and cryptographic functions was coded, and then used for the development of a crypto tool. We present the architecture and functionality of a hybrid ECC-AES cryptosystem which can be quickly deployed even in absence of Public Key Infrastructures and associated Certification Authorities. The tool was conceived for use in combination with readily available resources, e.g. email and possibly social networks. It allows secure exchange of files with associated ECDSA digital signature, providing the user with substantial flexibility and control of the security settings. Established protocols were used in an original way, notably exploiting direct embedding of the AES session key into an elliptic curve. The code has been developed in C++ entirely from scratch, with no use of pre-existing libraries. The implementation is associated with a web site http://www.elcrypto.com, www.elcrypto.com aimed at promoting the benefits of Elliptic Curve Cryptography.