  Recent studies have shown that developers have difficulties in using
cryptographic APIs, which often led to security flaws. We are interested to
tackle this matter by looking into what types of problems exist in various
crypto libraries. We manually studied 500 posts on Stack Overflow associated
with 20 popular crypto libraries. We realized there are 10 themes in the
discussions. Interestingly, there were only two questions related to attacks
against cryptography. There were 63 discussions in which developers had
interoperability issues when working with more than a crypto library. The
majority of posts (i.e. 112) were about encryption/decryption problems and 111
were about installation/compilation issues of crypto libraries. Overall, we
realize that the crypto libraries are frequently involved in more than five
themes of discussions. We believe the current initial findings can help team
leaders and experienced developers to correctly guide the team members in the
domain of cryptography. Moreover, future research should investigate the
similarity of problems at the API level among popular crypto libraries.
