IIS Cryptographic Implementation Using C++

Abstract

This Information and System Security project implements core public-key cryptography workflows in C++ instead of treating encryption as a black-box library call. The repository contains six standalone programs covering RSA, ElGamal, elliptic-curve cryptography, and their corresponding digital signature variants.

The implementation uses NTL for arbitrary-precision integers, prime generation, modular inverses, and modular exponentiation, with OpenSSL SHA-1 used to convert arbitrary messages into signed digests. Each program demonstrates the full lifecycle: parameter generation, key generation, encryption or signing, decryption or verification, and altered-signature rejection.

The ECC work goes deeper than API usage by implementing point addition, point doubling, scalar multiplication, message-to-curve mapping, and encryption/decryption on a 192-bit NIST-style curve.

What I Built

• The repository implemented full RSA, ElGamal, and ECC workflows instead of wrapping prebuilt library calls.
• Signature verification on authentic and tampered messages validated both success and failure paths in the cryptographic pipeline.
• The ECC implementation went deep into point arithmetic, scalar multiplication, and message-to-curve handling.

Impact

• Shows low-level security engineering and algorithmic understanding in a way that higher-level app projects cannot.
• Adds strong systems credibility through reproducible C++ builds and explicit cryptographic primitives.