  Previous studies have shown that developers regularly seek advice on online
forums to resolve their cryptography issues. We investigated whether users who
are active in cryptography discussions also use cryptography in practice. We
collected the top 1% of responders who have participated in crypto discussions
on Stack Overflow, and we manually analyzed their crypto contributions to open
source projects on GitHub. We could identify 319 GitHub profiles that belonged
to such crypto responders and found that 189 of them used cryptography in their
projects. Further investigation revealed that the majority of analyzed users
(i.e., 85%) use the same programming languages for crypto activity on Stack
Overflow and crypto contributions on GitHub. Moreover, 90% of the analyzed
users employed the same concept of cryptography in their projects as they
advised about on Stack Overflow.
