On the Condition and the Proof of the Existence of Perfect Secrecy Cryptosystem
完善保密密码体制的条件和存在性证明

Perfect secrecy of cryptosystem is one of the important methods weighing the security of secrecy system.Based on the deep analysis of the relationship among plaintext size,ciphertext size,key size and the key probability of perfect secrecy of cryptosystem,two necessary conditions for special perfect secrecy cryptosystem were presented and proved.This paper suggested an approach to build perfect secrecy cryptosystem and summarized four correlated restrictions.By researching a question about the existence of ...