I like to use cryptobib , because it gives me consistent results and it contains almost everything relevant to me.
However, as crypto.bib is over 725000 lines long, parsing it to create the bibliography takes a long time. This means that my $\LaTeX$ compile jobs take much too long.
I have now written a python script that will allow you to extract entries from large bibliographies.
This script will take your biblatex .
For crypto code it's important that it's time-invariant, otherwise it is vulnerable to timing attacks. I've had to build this time-invariant equality test from scratch, because I couldn't find something on Google. I hope it's useful to someone else.