The Discrete Logarithm Problem is well-known among cryptographers, for its
computational hardness that grants security to some of the most commonly used
cryptosystems these days. Still, many of these are limited to a small number of
candidate algebraic structures which permit implementing the algorithms. In
order to extend the applicability of discrete-logarithm-based cryptosystems to
a much richer class of algebraic structures, we present a generalized form of
exponential function. Our extension relaxes some assumptions on the exponent,
which is no longer required to be an integer.
Implementations of quantum key distribution as available nowadays suffer from
inefficiencies due to post processing of the raw key that severely cuts down
the final secure key rate. We present a simple model for the error scattering
across the raw key and derive "closed form" expressions for the probability of
a parity check failure, or experiencing more than some fixed number of errors.
Our results can serve for improvement for key establishment, as information
reconciliation via interactive error correction and privacy amplification rests
on mostly unproven assumptions.