Paper 2018/1095

Scalable One-Time Pad --- From Information Theoretic Security to Information Conservational Security

Wen-Ran Zhang

Abstract

Whereas it is widely deemed an impossible task to scale down One-Time Pad (OTP) key length without sacrificing information theoretic security or network traffic, this project started with the attempt to develop a paradigm of Scalable One-Time Pad (S-OTP) ciphers based on information conservational computing/cryptography (ICC). This line of research, however, hits a dead-end at the limitation of information entropy and computational precision for full information conservation when long messages are transmitted. The dead-end suggests a 2-phase study. First, to explore the boundaries of scalability with data compression to reduce a long message to a tiny minimum but assuming only partial information conservation. Second, to explore the possibility of scalability with full information conservation but with limited increase of network traffic for transmitting long messages with information theoretic security. This paper reports results of the first phase. This study suggests two future directions of ICC: (1) using S-OTP to scale down key length at the expense of limited increase of network traffic for full information conservation (See solution at https://eprint.iacr.org/2019/913.pdf ); (2) develop a type of quantum crypto machine for full information conservation.