Crypto Experts Advise What They Adopt

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.