Although
the AES algorithm is also subject to brute force attacks, it requires significantly more computing
power to crack than the DES algorithm does.
For more information on AES, including a command-line implementation of the algorithm, you
can visit http://aescrypt.sourceforge.net/.
Asymmetric Cryptography
Public-key cryptography does not suffer from key distribution problems, and that is why it is the
preferred encryption method for secure Internet communication. This method uses two keys, one
to encrypt the message and another to decrypt the message. The key used to encrypt the message
is called the public key because it is made available for all to see. The key used to decrypt the
message is the private key and is kept hidden.
Imagine that you want to send me a secure message using public-key encryption. Here is what
we need:
1. I must have a public and private key pair. Depending on the circumstances, I may generate
the keys myself (using special software) or obtain the keys from a key authority.
2. You want to send me a message, so you first look up my public key (or more accurately,
the software you are using looks it up).
3. You encrypt the message with the public key. At this point, the message can be decrypted
only with the private key (the public key cannot be used to decrypt the message).
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