high performance C++ OpenPGP library and tools
librnp is a cross-platform C++ library providing an implementation of OpenPGP (RFC4880). Unlike GPGME, it is standalone and doesn't call out to the gnupg binary. RNP is a set of tools built using this library providing key management and the usual encrypt/decrypt/sign/verify functions - it can replace gnupg for some uses.
Homepage: https://www.rnpgp.org/