A Secure and Efficient Mix-Network using Extended Binary Mixing Gate

A mix-network accepts a set of ciphertexts and outputs the corresponding plaintexts in a random order. It is an important tool in schemes requiring anonymity of messages, such as in secure e-voting and e-auction schemes. A mix-network is comprised of shuffling and decryption operations. A robust mix-network must provide proofs that it shuffles and decrypts its input ciphertexts and outputs their corresponding plaintexts correctly. Verifying such proofs is often a bottleneck affecting the performance of the mix-network. We propose a secure and efficient mix-network employing extended binary mixing gates (EBMGs) using batching techniques to re-encrypt the ciphertexts, and produce and verify the proofs of correct shuffling. The proposed mix-network offers sufficient anonymity and high performance level compared to other mix-network schemes.