HIME: Huge Integer Math and Encryption 

Library with encryption functions (public key/secret key) and huge integer math functions. RSA public key, AES (Rijndael) secret key encryption, SHA-256 hash function, PRNG: Blum-Blum-Shub and RSA, Diffie-Hellman. For every programming language.
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DeepCoder 

DeepCoder is a program to encrypt, decrypt and/or digitally sign e-mails and files using secret keys (passwords) or public keys. It can be used with any e-mail program or wordprocessor program. No plug-ins are required. Very easy to use!
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