arXiv:2206.01937

Digest of Quantum Stream Cipher based on Holevo-Yuen Theory

Masaki Sohma, Osamu Hirota

Published Jun 4, 2022• 0 citations

Abstract

So far, quantum key distribution (QKD) has been the main subject in the field of quantum cryptography, but that is not quantum cryptographic communication, it is only the ability to send keys for cryptographic purposes. To complete cryptographic communication, a technique for encrypting data is necessary, and the conventional cryptographic technique of mathematical symmetric key cipher or One Time Pad (OTP) is adopted in the discussion so far. However, OTP is not the ultimate cipher for data encryption, because it does not satisfy security conditions in the modern cryptology. Around 2000, a new quantum stream cipher was proposed as a technique to challenge the possibility of overcoming drawbacks of OTP in practical use. Recently, we have published some review papers on it in Entropy (Open access journal), and others. This paper introduces an overview and a back ground of our paper that is entitled Quantum stream cipher based on Holevo-Yuen theory.

DOI: 10.48550/arxiv.2206.01937

Related papers

Quantum Stream Cipher Based on Holevo–Yuen Theory

Masaki Sohma, Osamu Hirota

In this review paper, we first introduce the basic concept of quantum computer-resistant cryptography, which is the cornerstone of security technology for the network of a new era. Then, we will describe the positioning of mathematical cryptography and quantum cryptography, that are currently being researched and developed. Quantum cryptography includes QKD and quantum stream cipher, but we point out that the latter is expected as the core technology of next-generation communication systems. Various ideas have been proposed for QKD quantum cryptography, but most of them use a single-photon or similar signal. Then, although such technologies are applicable to special situations, these methods still have several difficulties to provide functions that surpass conventional technologies for social systems in the real environment. Thus, the quantum stream cipher has come to be expected as one promising countermeasure, which artificially creates quantum properties using special modulation techniques based on the macroscopic coherent state. In addition, it has the possibility to provide superior security performance than one-time pad cipher. Finally, we introduce detailed research activity aimed at putting the quantum stream cipher into practical use in social network technology.

EntropyMay 10, 20227 citations

Quantum Stream Cipher by Yuen-2000 Protocol

Osamu Hirota, Tetsuya Shimizu, Masaki Sohma +1 more

Since quantum key distribution protocol was invented in 1984, huge number of papers on quantum cryptography have been published. However, they have so many serious technical problems which should overcome difficulties. On the other hand, it is reasonable to develop a quantum version of the conventional mathematical symmetric key cipher. In 2000, Yuen protocol was invented to realize a quantum version of stream cipher. In this paper, we introduce the principle and recent progress on quantum stream cipher by Yuen 2000 protocol.

The Review of Laser EngineeringJan 1, 20081 citation

A quantum encryption design featuring confusion, diffusion, and mode of operation

Zixuan Hu, Sabre Kais

Quantum cryptography-the application of quantum information processing and quantum computing techniques to cryptography has been extensively investigated. Two major directions of quantum cryptography are quantum key distribution (QKD) and quantum encryption, with the former focusing on secure key distribution and the latter focusing on encryption using quantum algorithms. In contrast to the success of the QKD, the development of quantum encryption algorithms is limited to designs of mostly one-time pads (OTP) that are unsuitable for most communication needs. In this work we propose a non-OTP quantum encryption design utilizing a quantum state creation process to encrypt messages. As essentially a non-OTP quantum block cipher the method stands out against existing methods with the following features: 1. complex key-ciphertext relation (i.e. confusion) and complex plaintext-ciphertext relation (i.e. diffusion); 2. mode of operation design for practical encryption on multiple blocks. These features provide key reusability and protection against eavesdropping and standard cryptanalytic attacks.

arXiv:2010.03062Scientific ReportsDec 10, 202116 citations

Quantum stream cipher based on optical communications

Osamu Hirota, Kentaro Kato, Masaki Sohma +2 more

In 2000, an attractive new quantum cryptography was discovered by H.P.Yuen based on quantum communication theory. It is applicable to direct encryption, for example quantum stream cipher based on Yuen protocol(Y-00), with high speeds and for long distance by sophisticated optical devices which can work under the average photon number per signal light pulse: <n> = 1000 ~ 10000. In addition, it may provide information-theoretic security against known/chosen plaintext attack, which has no classical analogue. That is, one can provide secure communication, even the system has H(K)<<H(X). This is a challenge to overcome Shannon limit in the cryptography theory. In this paper, first, we give a brief review on the general logic of Yuen's theory. Then, we show concrete security analysis of quantum stream cipher to quantum individual measurement attacks. Especially by showing the analysis of Lo-Ko known plaintext attack, the feature of Y-00 is clarified. In addition, we give a simple experimental result on the scheme consisting of intensity modulation/direct detection optical communication.

arXiv:quant-ph/0407062Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEOct 19, 20046 citations

Quantum Stream Cipher Based on Holevo–Yuen Theory: Part II

Osamu Hirota, Masaki Sohma

This paper discusses the foundation of security theory for the Quantum stream cipher based on the Holevo-Yuen theory, which allows the use of "optical amplifiers". This type of cipher is a technology that provides information-theoretic security (ITS) to optical data transmission by randomizing ultrafast optical communication signals with quantum noise. In general, the quantitative security of ITS is evaluated in terms of the unicity distance in Shannon theory. However, the quantum version requires modeling beyond the Shannon model of a random cipher to utilize the characteristics of the physical layer. Therefore, as the first step, one has to develop a generalized unicity distance theory and apply it to the evaluation of security. Although a complete theoretical formulation has not yet been established, this paper explains a primitive structure of a generalization of the Shannon random cipher and shows that the realization of this is the generalized quantum stream cipher. In addition, we present several implementation methods of generalized quantum stream ciphers and their security.

EntropyNov 15, 20240 citations

Design of Quantum Stream Cipher: Part-I -Lifting the Shannon Impossibility Theorem-

Osamu Hirota

This paper is dedicated to the late Professor H.P. Yuen in commemoration to our 50-year friendship. He invented the concept of quantum stream cipher. It is designed based on a completely different concept from conventional ciphers. The purpose of this cipher is to provide information-theoretic security of long data and secret key with short key length. It is based on hiding the ciphertext of mathematical cipher with quantum noise, achieving unprecedented information-theoretic security in any cipher. The protocol corresponds to randomizing the ciphertext by means of differentiating the receiving performance of Bob with key and Eve without key according to the principle of quantum communication theory. In this paper, we introduce some progress on the specific method to develop from the standard type to generalized quantum stream cipher (Quantum Enigma Cipher). There are two methods for generalization. One is the additional randomization method by the product cipher form and the other is the M-th order extended quantum coding method. Here we discuss the former. The results proved that it has sufficient information-theoretic security against known plaintext attack on key in comparison with quantum data locking. The latter method will be reported in Part II.

arXiv:2503.14872Mar 19, 20250 citations