Re: encryption question

To answer the first part of your question...

Yes, you can create Private/Public encryption keys and throw away the
Private key forcing the originator to regenerate the key pair again, just
the same way they did the first time. Using the same Key Generator methods
and source input will produce the same key pair every time.

The other responses to your question actually touch on 2 separate parts of
encryption. Typically you encrypt Content with your Public key to keep
others from looking at it. You then create a Hash of the content and
encrypt this with your Private key, append it or prepend it to the file as a
fix block, (for example 256 bytes) with say your name and the Hash value and
use this as you "signature". Anyone can read the header block and decode it
using your Public key to see that it was indeed you that owns the file.
They would then compute the Hash of the remainder of the file (the part
encrypted with your Public Key) and compare that with your Hash you included
in the header block and that tells them the Encrpted Content has not been
changed.

DaveH



"Rael" <rael@xxxxxxxxxx> wrote in message
news:479f4640@xxxxxxxxxxxxxxxxxxxxxxxxx
Hi,

I would like to use an encryption method where no record of the secret key
is kept. (If the correct key is supplied the data will be unencrypted
correctly otherwise a meaningless stream will be returned.)
But how to know if the user has entered the correct password?

If I keep a "test" string stored somewhere, where I know what this string
value should be when unencrypted, will this comprimise security? IOW, if a
hacker has access to an encrypted string and knows what the unencrypted
value of this string is, can he work out the secret key?

I would like to know if the answer to this question depends on algorithm
used (i.e. public/private key pair or straightforward encryption
(blowfish?)). I will probably be using an encryption method from freeware
components streamsec or DCPCrypt.

Thanks alot to any advice,

Rael




.

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