From: Adam Back <aba@dcs.ex.ac.uk>
Date: Sat, 1 Nov 1997 03:16:52 +0800
To: FisherM@exch1.indy.tce.com
Subject: Re: PGP Employee on MKR
In-Reply-To: <2328C77FF9F2D011AE970000F84104A74933FD@indyexch_fddi.indy.tce.com>
Message-ID: <199710311817.SAA05405@server.test.net>
MIME-Version: 1.0
Content-Type: text/plain




Fisher Mark <FisherM@exch1.indy.tce.com> writes:
> >Scenario #2: employee quits jon in a huff, refuses to divulge
> >passphrase, lots of queued encrypted email -- what now?
> 
> Or lots of encrypted old email that contains useful information.
> Especially in a larger corporate environment, where an email system is
> deployed that uses a proprietary message store (like Microsoft Mail or
> Microsoft Exchange), people tend to use the mailboxes as storage
> containers.

Absolutely.  However it is better where this is possible to decrypt
the message (and optionally re-encrypt the messages to a long-lived
storage key) prior to storing in the mail folder.

I am lead to understand this is relatively easy to do with the plugin
APIs pgp are implementing within.

The advantage of using separate storage encryption keys is that you
can give the communications only encryption keys appropriate expiry
periods.

> It gets worse if these isn't a way to get the messages out of the
> vendor's message store conveniently -- if you want to keep old
> messages around, they _have_ to be stored in the vendor's message
> store.

PGP Inc already has this problem with their CMR approach -- when the
user forgets his passphrase there is no backup of the key.  So to
retain data availability they must have the recovery czar decrypt the
lot, and re-encrypt it to the users new key.  Messy.

I'm also not sure that they have automated this for the sorts of plug
environments you are talking about (eg. with monolithic 100Mb
microsoft exchange sent/received mail databases).

Which tends to suggest corporate users who are worried about the
password forgetting problem will copy the private keys on floppies.
This is bad because pgp5.x is not designed for this -- they will get
private signature keys too allowing forgeries.

Adam
-- 
Now officially an EAR violation...
Have *you* exported RSA today? --> http://www.dcs.ex.ac.uk/~aba/rsa/

print pack"C*",split/\D+/,`echo "16iII*o\U@{$/=$z;[(pop,pop,unpack"H*",<>
)]}\EsMsKsN0[lN*1lK[d2%Sa2/d0<X+d*lMLa^*lN%0]dsXx++lMlN/dsM0<J]dsJxp"|dc`