cryptlib - Strong encryption and authentication for apps
A security toolkit letting even less experienced programmers add encryption and authentication services to their apps, features that are becoming indispensable. The library hides low-level details of security from developers. It supports a variety of algorithms for symmetric/asymmetric encryption, authentication, and hashing. The library is free for non-commercial/shareware projects. It is written in C. ActiveX and C++ wrappers are available.