Threshold public-key encryption systems

Abstract

U ovom radu istražuje se koncept kriptografske sheme s pragom te prednosti takve sheme u odnosu na uobičajene kriptosustave. Istražene su postojeće kriptografske sheme s pragom: sheme za digitalni potpis (RSA, DSA) i za enkripciju (Paillier, Damgård-Jurik, ElGamal). Na temelju istraživanja, u sklopu rada razvijena je i objavljena Python biblioteka koja pruža mogućnost enkripcije i dekripcije s pragom, bazirana na ElGamalovom kriptosustavu s pragom. Uz to, biblioteka koristi i algoritam za raspodijeljeno generiranje ključeva. Provedeno je testiranje te analiza vremenske kompleksnosti biblioteke. Razvijena je jednostavna CLI aplikacija koja demonstrira korištenje biblioteke.This paper explores the concept of threshold cryptography and its advantages compared to usual cryptosystems. It delves into existing threshold cryptosystems: ones used for digital signatures (RSA, DSA) and ones used for encryption (Paillier, Damgård-Jurik, ElGamal). Following the research, a Python library for threshold encryption and decryption was developed, based on threshold ElGamal cryptosystem. The library also uses an algorithm for distributed key pair generation. The library was tested and time complexity analysis was done. A simple CLI application was developed to demonstrate functionalities of the library