Why subkeys?

[Per Tunedal]

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Hi,
Subkeys are very useful. You kan create a subkey for encryption with a 
shorter validity than the primary (signing) key. Thus you can create a new 
encryption key shortly before the subkey expires and keep the signatures on 
your primary key.

Implication:
- - If someone ever will be able to attack one of your encryption keys, that 
person will only be able to read documents encrypted to you during a 
limited time.
- - People you communicate with can trust your new encryption keys, because 
they have already signed your primary key.

Per Tunedal

At 15:20 2002-10-10 -0700, you wrote:
 >This mail was signed (PGP-MIME).
 >
 >,-----GnuPG output follows (current time: Fri, Oct 11 2002 - 09:55:31)--
 >|
 >|     Signature made 10/11/02 00:20:36  using DSA key ID A221559B
 >|     Can't check signature: public key not found
 >|
 >`-----------------------------------------------After watching this list for
 >a weekor so now, I'm curious about the use
 >of subkeys with GnuPG.  I don't have any subkeys, or at least I haven't
 >explicitly created any.  What is to be gained by subkeys on a key ring?
 >What is the relationship between subkeys and the "master" key?  Any
 >insight here would be greatly appreciated.
 >
 >Thanks,
 >
 >--
 >Doug Gorley | douggorley@shaw.ca     OpenPGP Key ID: 0xA221559B
 >Fingerprint: D707 DB92 E64B 69DA B8C7  2F65 C5A9 5415 A221 559B
 >Interested in public-key cryptography?    http://www.gnupg.org/ 

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