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Document Encryption and Public Key Technology
Using encryption on a standard desktop computer, it is possible for anyone to transmit information securely across the Internet, the same way that the military or governments do it. A widely available method requires a computer program that generates a linked pair of "keys"a public key and a private key. Both are needed. One undoes what the other one does.
The keys are like unique badges. A private key resides on your own computer, and you never give it out. A public key may be copied freely and distributed to anyone you want, or put on your home page or other places to give others easy access. You need both kinds because they are fundamentally linked, like the legs in a pair of pants. You can do two things with encryption technologymake a document unreadable by others or attach a digital signature. In either case, the document created with one key can only be decrypted or verified by using its linked key partner. Matching the keys is the essence of the process.
Keys work in two ways:
1. Others can use your public key to encrypt a confidential message only you will be able to decrypt (using your private key). You can encrypt a message using your private key that can be decrypted by anyone with access to your public key.
2. You can sign a message This is called "authenticating your digital signature" and assures the recipient that the file has not been altered.
Public and private keys are linked by a powerful cryptographic algorithm that would require major computer resources that no one today has to break. No one else's keys can decipher messages to you encrypted with your public key. And no one can pose as you by sending messages signed with your private key. For more information on encryption and the government's opposition to widespread public use of encryption technology, visit the web site of Pretty Good Privacy, Inc. (http://www.pgp.com/).
Kaye Vivian, ABC
http://www.cloud9.net/~kvivian
Copyright 1997 by Kaye Vivian ( kvivian@cloud9.net ). All rights reserved.
For permission to reprint, contact the author directly.
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