Usability Smells: An Analysis Of Developers' Struggle With Crypto Libraries

Green and Smith propose ten principles to make cryptography libraries more usable [14], but to what extent do the libraries implement these principles? We undertook a thematic analysis of over 2400 questions and responses from developers seeking help with 7 cryptography libraries on Stack Overflow; analyzing them to identify 16 underlying usability issues and studying see how prevalent they were across the 3 cryptography libraries for which we had the most questions for on Stack Overflow. Mapping our usability issues to Green and Smith's usability principles we identify 4 usability smells where the principles are not being observed. We suggest what developers may struggle the most with in the cryptography libraries, and where significant usability gains may be had for developers working to make libraries more usable.