A method of enciphering quantum states
arXiv:quant-ph/0006124 · doi:10.1088/0305-4470/34/13/305
Abstract
In this paper, we propose a method of enciphering quantum states of two-state systems (qubits) for sending them in secrecy without entangled qubits shared by two legitimate users (Alice and Bob). This method has the following two properties. First, even if an eavesdropper (Eve) steals qubits, she can extract information from them with certain probability at most. Second, Alice and Bob can confirm that the qubits are transmitted between them correctly by measuring a signature. If Eve measures m qubits one by one from n enciphered qubits and sends alternative ones (the Intercept/Resend attack), a probability that Alice and Bob do not notice Eve's action is equal to (3/4)^m or less. Passwords for decryption and the signature are given by classical binary strings and they are disclosed through a public channel. Enciphering classical information by this method is equivalent to the one-time pad method with distributing a classical key (random binary string) by the BB84 protocol. If Eve takes away qubits, Alice and Bob lose the original quantum information. If we apply our method to a state in iteration, Eve's success probability decreases exponentially. We cannot examine security against the case that Eve makes an attack with using entanglement. This remains to be solved in the future.
21 pages, Latex2e, 10 epsf figures. v2: 22 pages, added two references, several clarifying sentences are added in Sec. 5, typos corrected, a new proof is provided in Appendix A and it is shorter than the old one. v3: 23 pages, one section is added
References in corpus (12)
- Polynomial-Time Algorithms for Prime Factorization and Discrete Logarithms on a Quantum Computer
- Experimental quantum teleportation
- Mixed State Entanglement and Quantum Error Correction
- Elementary gates for quantum computation
- Quantum cryptography: Public key distribution and coin tossing
- Purification of Noisy Entanglement and Faithful Teleportation via Noisy Channels
- Measurement of conditional phase shifts for quantum logic
- Quantum privacy amplification and the security of quantum cryptography over noisy channels
- Stabilizer Codes and Quantum Error Correction
- A Simple Quantum Computer
- Optimal Encryption of Quantum Bits
- Private Quantum Channels and the Cost of Randomizing Quantum Information