The NTRU public-key cryptosystem provides a Java implementation of the NTRUEncrypt and NTRUSign algorithms. Both algorithms are considered safe against quantum computer attacks. A C port of NTRUEncrypt is available, as well.
SilverTunnel-NG is a Java library that handles all the Tor connection work for easy integration into new or existing projects. You can connect to any server on the Internet anonymously; connect to a hidden service inside the Tor network; provide a hidden service; and more.