关键词: 密码学，无条件安全，密钥协商，卫星信道模型，初始化

Abstract: The satellite broadcasting channel model is one of the practical models to realize unconditional security. However, the satellite scenario suffers from some drawbacks such as the receiving synchronization and high communication costs. ho overcome these drawbacks, a virtual satellite broadcasting channel model was proposed. The proposed model uses virtual binary symmetric channels to simulate a satellite model. The model only uses XOR operations to perform the initialization process of the secret key agreement. Therefore, the proposed model is efficient, and easy to implement, to synchronize, and has lower communication costs. It was proven that in the proposed model, the wiretapper has a larger receiving bit error probability.

Key words: Cryptography, Unconditional security, Secret key agreement, Satellite scenario, Initialization