  Quantum Key Distribution(QKD) thrives to achieve perfect secrecy of One time
Pad (OTP) through quantum processes. One of the crucial components of QKD are
Quantum Random Number Generators(QRNG) for generation of keys. Unfortunately,
these QRNG does not immediately produce usable bits rather it produces raw bits
with high entropy but low uniformity which can be hardly used by any
cryptographic system. A lot of pre-processing is required before the random
numbers generated by QRNG to be usable. This causes a bottle neck in random
number generation rate as well as QKD system relying on it. To avoid this
lacuna of post-processing methods employed as a central part of Quantum Random
Number Generators alternative approaches that satisfy the entropy(non
determinism) and quantum security is explored. Pseudorandom generators based on
quantum secure primitives could be an alternative to the post-processing
problem as PRNGs are way more faster than any random number generator employing
physical randomness (quantum mechanical process in QRNG) as well as it can
provide uniform bits required for cryptography application. In this work we
propose a pseudorandom generator based on post quantum primitives. The central
theme of this random number generator is designing PRNG with non deterministic
entropy generated through hard lattice problem - Learning with errors. We
leverage the non determinism by Gaussian errors of LWE to construct
non-deterministic PRNG satisfying the entropy requirement of QKD. Further, the
paper concludes by evaluating the PRNG through Die-Harder Test.
