WBZUC:novel white-box ZUC-128 stream cipher

White-box cryptography is critical in a communication system to protect the secret key from being disclosed in a cryptographic algorithm code implementation. The stream cipher is a main dataflow encryption approach in mobile communication. However, research work on white-box cryptographic implementation for stream cipher is rare. A new white-box Zu Chongzhi-128(ZUC-128) cryptographic implementation algorithm named WBZUC was proposed. WBZUC adopts lookup table and random coding in the non-linear function to make the intermediate value chaotic without changing the final encryption result. Thus, the WBZUC algorithm’s security gets improved compared with the original ZUC-128 algorithm. As for the efficiency, a test experiment on WBZUC shows that the average speed of key generation, encryption, and decryption can reach at 33.74 kbit/s, 23.31 kbit/s, 24.06 kbit/s respectively. Despite its running speed is relatively a bit lower than original ZUC-128 algorithm, WBZUC can provide better security and comprehensive performance in mobile communication system environment.