Related papers: An immunity against correlation attack on quantum …

This paper shall investigate Yuen protocol, so called Y-00, which can realize a randomized stream cipher with high bit rate(Gbps) for long distance(several hundreds km). The randomized stream cipher with randomization by quantum noise based…

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…

In our previous work, it was demonstrated that the attacker could not pin-down the correct keys to start the Y00 protocol with a probability of one under the assistance of unlimitedly long known-plaintext attacks and optimal quantum…

In 2000, an attractive new quantum cryptography was discovered by H.P.Yuen, which can realize secure communication with high speeds and at long distance by conventional optical devices. Recently, a criticism of the Yuen protocol, so called…

We review the notion of a classical random cipher and its advantages. We sharpen the usual description of random ciphers to a particular mathematical characterization suggested by the salient feature responsible for their increased…

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…

The previous work showed that the Y00 protocol could stay secure with the eavesdropper's guessing probability on the secret keys being strictly less than one under an unlimitedly long known-plaintext attack with quantum memory. However, an…

The potential weakness of the Y-00 direct encryption protocol when the encryption box ENC in Y-00 is not chosen properly is demonstrated in a fast correlation attack by S. Donnet et al in Phys. Lett. A 35, 6 (2006) 406-410. In this paper,…

What obstructs the realization of useful quantum cryptography is single photon scheme, or entanglement which is not applicable to the current infrastructure of optical communication network. We are concerned with the following question: Can…

New quantum cryptography, often called Y-00 protocol, has much higher performance than the conventional quantum cryptographies. It seems that the conventional quantum cryptographic attacks are inefficient at Y-00 protocol as its security is…

It is claimed in Phys. Lett. A by T. Nishioka et. al. 327 (2004) 28-32, that the security of Y-00 is equivalent to that of a classical stream cipher. In this paper it is shown that the claim is false in either the use of Y-00 for direct…

Although quantum key distribution is regarded as promising secure communication, security of Y00 protocol proposed by Yuen in 2000 for the affinity to conventional optical communication is not well-understood yet; its security has been…

Nishioka et al claim in [1], elaborating on their earlier paper [2], that the direct encryption scheme called Y-00 [3,4] is equivalent to a classical non-random additive stream cipher, and thus offers no more security than the latter. In…

Attacks on classical cryptographic protocols are usually modeled by allowing an adversary to ask queries from an oracle. Security is then defined by requiring that as long as the queries satisfy some constraint, there is some problem the…

This paper is the part-II of the previous paper and introduces the world of Yuen's concept. In the theory of cryptology, the Shannon impossibility theorem states that the upper bound of the security of a plaintext against a ciphertext-only…

We present a quantum probabilistic encryption algorithm for a private-key encryption scheme based on conjugate coding of the qubit string. A probabilistic encryption algorithm is generally adopted in public-key encryption protocols. Here we…

We consider two-way continuous-variable quantum key distribution, studying its security against general eavesdropping strategies. Assuming the asymptotic limit of many signals exchanged, we prove that two-way Gaussian protocols are immune…

This paper critically analyzes the Y00 protocol, a quantum noise-based stream cipher proposed to enhance classical cryptographic methods through quantum mechanical properties. Despite its promise, we reveal a structural vulnerability that…

Here we present a new protocol for controlled quantum key agreement and another protocol for key agreement with a specific focus on the security analysis. Specifically, detailed security proof is provided against impersonated fraudulent…

This research note II introduces a way to understand a basic concept of the quantum enigma cipher. The conventional cipher is designed by a mathematical algorithm and its security is evaluated by the complexity of the algorithm in security…