Related papers: Fake one-time pad cannot be used to improve the ef…

One-time pad encrypted files can be sent through Internet channels using current Internet protocols. However, the need for renewing shared secret keys make this method unpractical. This work shows how users can use a fast physical random…

Quantum information is a valuable resource which can be encrypted in order to protect it. We consider the size of the one-time pad that is needed to protect quantum information in a number of cases. The situation is dramatically different…

A classical one-time pad allows two parties to send private messages over a public classical channel -- an eavesdropper who intercepts the communication learns nothing about the message. A quantum one-time pad is a shared quantum state…

When elementary quantum systems, such as polarized photons, are used to transmit digital information, the uncertainty principle gives rise to novel cryptographic phenomena unachievable with traditional transmission media, e.g. a…

A two-layer quantum protocol for secure transmission of data using qubits is presented. The protocol is an improvement over the BB84 QKD protocol. BB84, in conjunction with the one-time pad algorithm, has been shown to be unconditionally…

Quantum secure direct communication is the direct communication of secret messages without first producing a shared secret key. It maybe used in some urgent circumstances. Here we propose a quantum secure direct communication protocol using…

A process for the secure transmission of data is presented that has to a certain degree the advantages of the one-time pad (OTP) cipher, that is, simplicity, speed, and information-theoretically security, but overcomes its fundamental…

When I was smaller, a five megabyte fixed disk cost $5,000, a 300 bps modem cost hundreds of dollars, and communication links were intercepted by attaching devices to the target subscriber's local loop. From then to now there have been…

Quantum key distribution (QKD) together with one time pad encoding can provide information-theoretical security for communication. Currently, though QKD has been widely deployed in many metropolitan fiber networks, its implementation in a…

We describe an encrypted communication principle that can form a perfectly secure link between two parties without electronically saving either of their keys. Instead, cryptographic key bits are kept safe within the unique mesoscopic…

We investigate how a classical private key can be used by two players, connected by an insecure one-way quantum channel, to perform private communication of quantum information. In particular we show that in order to transmit n qubits…

Unconditionally secure physical key distribution schemes are very slow, and it is practically impossible to use a one-time-pad based cipher to guarantee unconditional security for the encryption of data because using the key bits more than…

Quantum and private communications are affected by a fundamental limitation which severely restricts the optimal rates that are achievable by two distant parties. To overcome this problem, one needs to introduce quantum repeaters and, more…

Noise causes severe difficulties in implementing quantum computing and quantum cryptography. Several schemes have been suggested to reduce this problem, mainly focusing on quantum computation. Motivated by quantum cryptography, we suggest a…

Classical one-time-pad key can only be used once. We show in this Letter that with quantum mechanical information media classical one-time-pad key can be repeatedly used. We propose a specific realization using single photons. The reason…

We discuss aspects of secure quantum communication by proposing and analyzing a quantum analog of the Vernam cipher (one-time-pad). The quantum Vernam cipher uses entanglement as the key to encrypt quantum information sent through an…

Quantum communication enables the implementation of tasks that are unachievable with classical resources. However, losses on the communication channel preclude the direct long-distance transmission of quantum information in many relevant…

A revised version will be uploaded later. In this Letter, it is shown that the one-time-pad key in the Vernam cipher can be repeatedly used with unconditional security using quantum media. The security proof is given with two explicit…

We characterize the complete set of protocols that may be used to securely encrypt n quantum bits using secret and random classical bits. In addition to the application of such quantum encryption protocols to quantum data security, our…

The problem of secure broadcasting with independent secret keys is studied. The particular scenario is analyzed in which a common message has to be broadcast to two legitimate receivers, while keeping an external eavesdropper ignorant of…