Реферат: The Necessity Of Computer Security Essay Research

known only to its owner. Though either key can be used to encipher or to

decipher data encrypted with its mate, in most instances, the public key is

employed for encoding, and the private key for decoding. Thus, anyone can send

a secret message to anyone else by using the addressee’s public key to encrypt

its contents. But only the recipient of the message can make sense of it, since

only that person has the private key.

A public key cryptosystem is called the PGP, for Pretty Good Privacy.

Designed by Phil Zimmerman, this program is freely distributed for the purpose

of giving the public the knowledge that whatever communications they pass, they

can be sure that it is practically unbreakable.

PGP generates a public and private key for the user using the RSA technique.

The data is then encrypted and decrypted with the IDEA algorithm – which is

similar to the DES, but the work factor to decode the encrypted message by brute

force is much higher than what the DES could provide. The reason why the RSA is

used only when generating the keys is that the RSA takes a very long time to

encrypt an entire document, where using the RSA on the keys takes a mere

fraction of the time.

At this time, Zimmerman is bing charged by the US government for his effort

in developing the PGP. The government considers encryption as a weapon, and

they have established regulations controlling or prohibiting the export of

munitions. Since the PGP is a powerful encryption program, it is considered and

can be used as a powerful weapon and may be a threat to national security.

On the Internet, it is clear that many people all over the world are

against the US government’s effort on limiting the PGP’s encryption capabilities,

and their reason is that the ban infringes on the people’s right to privacy.

The PGP must not be treated only as a weapon, for it contains analogies

that are not used in wartime. One of them is authentication. The two-key

cryptosystem is designed with authentication in mind: Using someone’s public key

to encrypt enables only the owner of the private key to decrypt the same message.