RE: Proposal for stating key type in Commonline subject lines-Reply

[PAUL LOGSTON <PLOGSTON@usagroup.com>]

The main reason for using the subject line is so that the person
downloading the mail can filter it by patterns in the subject line. 
Otherwise, the receiver would have to download the entire message to
see this information.

>>> "Thien, Will" <will.thien@tgslc.org> 03/20/98 08:30am >>>
I know this is just my ignorance. Can we just encrypt the attachments
and use the message area for other information like encryption type or
other things we could standardize ? This would leave the subject area
alone. Is the reason we only use the subject area is because of old
CompuServe design ?




> -----Original Message-----
> From:	PAUL LOGSTON [SMTP:PLOGSTON@usagroup.com]
> Sent:	Thursday, March 19, 1998 9:38 AM
> To:	cl-elec-exch@lists.glhec.org
> Subject:	Proposal for stating key type in Commonline subject
> lines
> 
> 
> [Adminstrivia: When I use the word "Decrypt", I actually mean "Decrypt
> and Verify Signature".  I'm just too lazy to type that every time.]
> 
> During last week's conference call, we determined that it would be
> useful
> to specify the key type (RSA or D-H/DSS) in the subject line in the
> message header, so we could know which key type to use to decrypt
the
> message and verify the signature.
> 
> The reason we need to know this information is that we may be using
> two
> separate PGP products to decrypt files -- one for the RSA keys and one
> for D-H/DSS.  This is due to the fact that PGP's two programming
> interfaces (the Toolkit and the SDK) only support one key type each. 
> Specifically, the PGP/ViaCrypt Toolkit only supports RSA keys and the
> SDK
> only supports D-H/DSS.  And, since we are using different tools for
> each
> key type, we would likely need to keep separate key rings by key type.
> 
> All of this points to needing to know the key type used for the
> encryption
> before actually processing the file.
> 
> However, it is pretty late in the game to be changing the subject
> lines for
> CommonLine, since a lot of us (me included) already have code written
> that looks for and specifies the old subject lines.  So, specifying
> the key
> type must:
> 
> a) be optional, and
> b) be compatible.
> 
> There for, I propose adding an optional identifier after the old
> CommonLine
> subject string, but before the optional identifying information.  That
> identifier should simply be either "KEYRSA" or "KEYD-H", enclosed in
> brackets.  So, in general, our new subject line format would be:
> 
>     file-identifying-subject [KEYRSA | KEYD-H] <unique identifying
> number>
> 
> The reason for the delimiters around the key type is: a) it is more
> readable (IMHO) and b) it makes it easier to parse automatically.  The
> reason I added the phrase "KEY" to the identifiers is simply to drive
> home
> the purpose of the field.
> 
> For example, a CommonLine v3 App Send file's subject could look like
> this:
>     COM03 APP SEND [KEYRSA] <199803180017>
> 
> A CommonLine key update transaction with a Diffie-Hellman key would
> look like:
>     CL COMM UPDATE [KEYD-H] <USA GROUP GUARANTEE SERVICES>
> 
> Since the Key Type is optional, the following is a CommonLine v2 App
> Response using RSA keys:
>     COM96 APP RESP <GC19140201>
> 
> Comments?