Tar the directory(s) and use GnuPG/libgcrypt aes-256-gcm https://www.gnupg.org/documentation/manuals/gcrypt/Available-cipher-modes.html https://www.gnupg.org/do

Tar the directory(s) and use GnuPG/libgcrypt aes-256-gcm https://www.gnupg.org/documentation/manuals/gcrypt/Available-cipher-modes.html https://www.gnupg.org/documentation/manuals/gcrypt/Available... OpenSSL is on every system and can encrypt files with aes-256-gcm if for whatever reasons libgcrypt can't be used http://stackoverflow.com/questions/12153009/openssl-c-example-of-aes-gcm-using-evp-interfaces http://stackoverflow.com/questions/12153009/openssl-c-exampl... Tarsnap you can copy keys to any platform that will run Tarsnap http://www.tarsnap.com/man-tarsnap-keygen.1.html http://www.tarsnap.com/man-tarsnap-keygen.1.html http://jamesoff.net/site/2009/09/10/tarsnap-under-cygwin/ http://jamesoff.net/site/2009/09/10/tarsnap-under-cygwin/