Meaning of Encryption Ratios

[tinkerC]

Simply, what does 128-bit encryption mean? How do you achive it in code? What about 64-bit? Possibly 4096-bit ( slow, but possible? ) ? I am newbie to coding Crypto apps. Please give me a bit of help, any will be appriciated.

[mischief]

basically, the key size represents the maximum possible security that the cryptographic algorithm can provide, since the slowest possible method would be brute-force. however the provided security may be lower if there is a lower know attack complexity.

http://en.wikipedia.org/wiki/Key_size

some good reads on crypto are here: http://www.cryptopp.com/wiki/Recommended_Books

some good APIs for crypto (C & C++): CryptoPP, Botan, and (perhaps obviously) OpenSSL.

other than that, wikipedia is decent for understanding crypto terminology.