Privacy and authenticity are two main tasks for secure communication. In this paper, a quantum authenticated encryption scheme is proposed. This scheme is devised to encrypt and authenticate classical information using quantum states. We assume that Alice and Bob share a classical bits string y as their private key. Alice generates quantum cipher text and authentication tag using her secret key. Bob can decrypt and verify the authenticity of the received message. Security analysis shows that the proposed protocol is a computationally secure encryption and statistically secure authentication scheme.
Privacy and authenticity are two main tasks for secure communication. In this paper, a quantum authenticated encryption scheme is proposed. This scheme is devised to encrypt and authenticate classical information using quantum states. We assume that Alice and Bob share a classical bits string y as their private key. Alice generates quantum cipher text and authentication tag using her secret key. Bob can decrypt and verify the authenticity of the received message. Security analysis shows that the proposed protocol is a computationally secure encryption and statistically secure authentication scheme.
Authentication is a well-studied area of classical cryptography: a sender A and a receiver B sharing a classical secret key want to exchange a classical message with the guarantee that the message has not been modified or replaced by a dishonest party with control of the communication line. In this paper we study the authentication of messages composed of quantum states. We give a formal definition of authentication in the quantum setting. Assuming A and B have access to an insecure quantum channel and share a secret, classical random key, we provide a non-interactive scheme that enables A to both encrypt and authenticate an m qubit message by encoding it into m+s qubits, where the error probability decreases exponentially in the security parameter s. The scheme requires a secret key of size 2m+O(s). To achieve this, we give a highly efficient protocol for testing the purity of shared EPR pairs. It has long been known that learning information about a general quantum state will necessarily disturb it. We refine this result to show that such a disturbance can be done with few side effects, allowing it to circumvent cryptographic protections. Consequently, any scheme to authenticate quantum messages must also encrypt them. In contrast, no such constraint exists classically. This reasoning has two important consequences: It allows us to give a lower bound of 2m key bits for authenticating m qubits, which makes our protocol asymptotically optimal. Moreover, we use it to show that digitally signing quantum states is impossible.
Classical and quantum message authentication protocols were studied. A classical message authenticated encryption protocol based on quantum one-way functions was proposed. It was demonstrated that the proposed protocol was not only a secure encryption scheme, but also a secure authentication scheme. Using the authenticated encryption protocol as a sub-protocol, a quantum message authentication scheme was addressed. Compared with the scheme addressed by BARNUM et al, this protocol economizes the keys shared between two communication parties. The security of the quantum message authentication scheme is also shown.
This paper presents a simple, but efficient class of non-interactive protocols for quantum authentication of m-length clas sical messages. The message is encoded using a classical linear algebraic code C[n,m,t]. We assume that Alice and Bob share a classical secret key, xAB, of n bits. Alice creates n qubits based on the code word and the key, that indicates the bases used to create each qubit. The quantum states are sent to Bob through a noiseless quantum channel. We calculate the failure probability of the protocol considering several types of attacks.
Most of the quantum authentication protocols are used to authenticate quantum messages.In this paper, by using a pair of non-entangled qubits, a quantum authentication protocol of classical messages is proposed.In the pair of qubits, the first one is used to carry a bit message, and the second one is used as a tag to authenticate the classical message.In our protocol, a bit string instead of a sequence of maximally entangled states is used directly as an authentication key, so the authentication key can be easily stored offline.On the other hand, in our protocol, a unitary operation UA is chosen to encrypt the qubits so that the successful probability of all attacks analyzed is less than one.Our quantum authentication protocol is secure against various attacks such as the no-message attack and message attacks.
The demands for secure communication systems have been growing rapidly as technologies in computer networks advance. However, classical cryptography employed in network systems is only secure when malicious users do not have enough computational power to break the security in a practical amount of time. Quantum cryptography provides theoretically unbreakable security since its security relies on quantum mechanical properties. This dissertation resolves the weakness of classical cryptography in computer networks by developing novel cryptographic schemes. First, a new encryption scheme, quantum commutative encryption (QCE), has been developed by utilizing quantum superposition states. The analysis of possible attacks to the developed encryption scheme, the advantages of the developed scheme, and the requirements to utilize the developed scheme in a communication system are presented. Also, an example of realization with current technologies is shown.
Considering all the characteristics of the developed encryption scheme, a key distribution protocol, two authentication protocols, secret sharing scheme, and the possible practical application of the secret sharing scheme are designed by making use of the developed encryption scheme. This dissertation also discusses the security analysis for each developed scheme. All developed quantum cryptographic schemes are theoretically unbreakable and can be realized with current technologies.
The main contributions of this dissertation are not only the proposal of novel schemes, but also a demonstration of how quantum mechanical properties can be utilized in computer engineering/science.
Quantum authentication protocol can be used to authenticate classical messages in a secure manner. In this paper, by using the cryptographic hash function and non-orthogonal qubits, a quantum authentication protocol of classical messages is proposed. In our protocol, the classical messages and their corresponding tags are encoded as nonorthogonal qubits. The message receiver decodes the classical messages and their corresponding tags from the received qubits by using the authentication key. To verify the validity of the received classical messages, the message receiver verifies whether the hash values of the decoded classical messages are equal to the corresponding tags. Our scheme can be proved to be secure against forgery attack and measurement attack. On the other hand, the authentication key is a binary string, which can be securely obtained and easily saved. What is more, because the authentication key remains secure after executing the authentication protocol, it provides the possibility of reusing the authentication key.