Quantum wiretap channel with non-uniform random number and its exponent and equivocation rate of leaked information
This work addresses a practical implementation problem in quantum cryptography for secure communication systems, but it appears incremental as it modifies an existing code requirement rather than introducing a new paradigm.
The paper tackles the difficulty of preparing a perfectly uniform auxiliary random variable for quantum wiretap channel codes by proposing a code that only requires a non-uniform distribution, and it evaluates the exponential decreasing rate of leaked information and derives its equivocation rate.
A usual code for quantum wiretap channel requires an auxiliary random variable subject to the perfect uniform distribution. However, it is difficult to prepare such an auxiliary random variable. We propose a code that requires only an auxiliary random variable subject to a non-uniform distribution instead of the perfect uniform distribution. Further, we evaluate the exponential decreasing rate of leaked information and derive its equivocation rate. For practical constructions, we also discuss the security when our code consists of a linear error correcting code.