bibliographystyle{ACM-Reference-Format}
bibliography{mybibliography,abbrev3,crypto}

This is BibTeX, Version 0.99d (TeX Live 2017/Debian)
The top-level auxiliary file: main.aux
The style file: ACM-Reference-Format.bst
A level-1 auxiliary file: appendix.aux
Database file #1: mybibliography.bib
Database file #2: abbrev3.bib
Database file #3: crypto.bib
Sorry---you've exceeded BibTeX's hash size 100000
Aborted at line 291526 of file crypto.bib
(That was a fatal error)

Process exited with error(s)

bibliography{mybibliography}
bibliography{abbrev3}
bibliography{crypto}

documentclass{article}
usepackage{hyperref}
begin{document}

    nocite{*}
    bibliographystyle{ACM-Reference-Format}
    bibliography{abbrev3,crypto}

end{document}