Quantum-secure covert communication on bosonic channels

Quantum-secure covert communication on bosonic channels.

Computational encryption, information-theoretic secrecy and quantum cryptography offer progressively stronger security against unauthorized decoding of messages contained in communication transmissions. However, these approaches do not ensure stealth--that the mere presence of message-bearing transmissions be undetectable. We characterize the ultimate limit of how much data can be reliably and ...

Quantum capacities of bosonic channels.

We investigate the capacity of bosonic quantum channels for the transmission of quantum information. We calculate the quantum capacity for a class of Gaussian channels, including channels describing optical fibers with photon losses, by proving that Gaussian encodings are optimal. For arbitrary channels we show that achievable rates can be determined from few measurable parameters by proving th...

Secure Long-Distance Quantum Communication over Optical Fiber Quantum Channels

In today's communication networks, the widespread use of optical fiber and passive optical elements allows to use quantum key distribution (QKD) in the current standard optical network infrastructure. In the past few years, quantum key distribution schemes have attracted much study. The security of modern cryptographic methods, like asymmetric cryptography, relies heavily on the problem of fact...

Gaussian bosonic synergy: quantum communication via realistic channels of zero quantum capacity

As with classical information, error-correcting codes enable reliable transmission of quantum information through noisy or lossy channels. In contrast to the classical theory, imperfect quantum channels exhibit a strong kind of synergy: there exist pairs of discrete memoryless quantum channels, each of zero quantum capacity, which acquire positive quantum capacity when used together. Here we sh...

A Secure Quantum Communication Protocol Using Insecure Public Channels