Full Disclosure: Re: stealing ssh keys

[Jeffrey Walton <noloader () gmail com>]

On Fri, Oct 26, 2012 at 10:49 PM, Raj Mathur (राज माथुर)
<raju () linux-delhi org> wrote:
> On Thursday 25 Oct 2012, Ivaylo Hubanov wrote:
> > Yes Raj,
> > You almost got the RSA encryption/decryption flow. :) Just the
> > private key is used to sign the data and not to encrypt it.
> We're splitting hairs here :) but the private key is actually used to
> encrypt.  That encryption is called a signature.
I hate to split hairs, but "encrypt with the private key" is not a
valid cryptographic transform.

> Except, what you encrypt with the private key is a digest of the
> message, not the whole message itself.
When you sign, you treat the hash as an instance of cipher text and
you perform the inverse transform - you are "decrypting with the
private key"

Jeff

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