Distributed Paillier Cryptosystem without Trusted Dealer

Amirreza Hamidi, Hossein Ghodosi

Carmit Hazay, Gert Læssøe Mikkelsen, Tal Rabin +1 more

Thijs Veugen, Thomas Attema, Gabriele Spini

We consider the problem of securely generating the keys of the Paillier crypto system [11] with (t; n) threshold decryption, without a trusted dealer. Nishide and Sakurai [10] describe a solution, secure inthe malicious model. We use their ideas to make a simpler solution for the semi-honest model, and further introduce a few optimisations. We implement the secure key generation protocol on a single computer, andconsider its performance.

한대완

Giles Brassard

Ragdah Ahmed Qasim, Hamza B. Habib, Rifaat Z. Khalaf

This article proposes a new encryption algorithm based on two cryptographic techniques which are the three-pass protocol and the Paillier cryptosystem. Using the three-pass protocol makes it possible for one party to safely send a message to another party without exchanging or distributing encryption secrets. In each pass in the proposed algorithm, each party uses their private pair of prime numbers to calculate the modular number. That means they use their public and private keys to perform the encryption and decryption. Moreover, the encryption and the decryption on the sender side are performed by the Paillier cryptosystem which is based on the difficulty of finding the inverse modular of the public key. In the proposed algorithm, less information is shared between the two parties and that makes it more secure against attacks. The results show that the proposed algorithm needs less time to perform the encryption and decryption compared with the classic algorithm. Therefore, the proposed algorithm is more secure, fast and reliable for sending and receiving data compared with the classic algorithm.