[E-trademarks] cryptographic signatures? (was Applications owned by same owners no longer examined together?)

[Carl Oppedahl]

Thank you Kevin and Ken for posting.

In the world of cryptography there are two things that might arise:

  * An email message might be "encrypted".  If it is encrypted, then
    most people who somehow come into possession of the email message
    would not be able to read it.   Only someone who is in possession of
    the private decryption key would be able to decrypt the message and
    read it.
  * An email message might be cryptographically "signed".  If it is
    signed, then the email message contains a cryptographic signature. 
    The signature permits the recipient of the email message to confirm
    (if they wish) that the message has not been tampered with along the
    way.  The signature also permits the recipient of the email message
    to confirm (if they wish) that the message really came from the
    person that it claims to have come from.  Another way to say this is
    that it provides non-deniability -- the sender cannot deny that he
    or she was the sender, because only he or she could have signed it.

Most signed email messages also provide to the recipient what is called 
the "public key" of the sender.  This permits the recipient R, if they 
so choose, to send email messages to that sender S with the protection 
of encryption.  R's email client will likely have automatically stored 
the public key of S locally for future use. So for example R gets ready 
to send an email to S and R's email client may encrypt the to-be-sent 
email message to S.  And then R's email client sends the encrypted email 
message to S.  S uses his or her private key to decrypt the email message.

Some email messages are both signed and encrypted.   I'd guess that what 
happens very often is that if a sender of an email message encrypts it, 
the sender also signs it.

If anybody sees a posting from me on a listserv, by definition it is not 
encrypted.  Any email client that says my email posting to a listserv is 
encrypted is broken and needs fixing.

Many of my email postings to the listservs are signed.  I suppose what 
must sometimes happen is that somebody who is reading one of my postings 
might have an email client that makes a big mistake in its 
interpretation or handling of the cryptographic signature.

If you were to click around in your email client, very likely you could 
find a place where your email client methodically stores all of the 
public keys that it has ever received from people like me. You could 
look in that place, and you would very likely see a public key for 
carl at oppedahl.com that was issued by a service provider called Sectigo 
and that will expire in October of 2025.

On 2/10/2025 8:19 AM, Kevin Grierson via E-trademarks wrote:
>
> Ken,
>
> Regarding your post script, occasionally Outlook shows Carl’s emails 
> as encrypted, and then the message is blank, but there is an 
> attachment that has the message itself.  This happens with a couple of 
> clients, who claim that they are not trying to encrypt their 
> emails—perhaps a function of their email service?
>
> kwg
>
> *From:*E-trademarks <e-trademarks-bounces at oppedahl-lists.com> *On 
> Behalf Of *Ken Boone via E-trademarks
> *Sent:* Sunday, February 9, 2025 3:55 PM
> *To:* E-Trademarks at oppedahl-lists.com
> *Cc:* Ken Boone <boondogles at hotmail.com>
> *Subject:* Re: [E-trademarks] Applications owned by same owners no 
> longer examined together?
>
> PS - Does anyone else have any problems viewing postings from Carl?  
> On my laptop with Microsoft Edge, my email viewer spins and spins over 
> Carl's postings.  I typically switch to my Fire tablet and forward 
> Carl's posting to myself to view Carl's posting.  Or I switch from 
> Edge to Chrome.  Just me?
>
>
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