[cryptography] Email encryption for the wider public

Givon Zirkind givonne at gmx.com
Fri Sep 19 06:46:36 EDT 2014


this is an interesting point.  since google scrougles your emails and 
their aup says you agree to let them, by machine, sift through your 
data, to target you for marketing--Google Analytic's targeted ads--how 
receptive would Google or any freemail provider be, to an innate 
encryption scheme.  if i were a lawyer for Google, I could even argue 
that such a user has violated Google's AUP and the account can be shut down.

On 9/19/2014 5:33 AM, Henry Augustus Chamberlain wrote:
> Hi all,
>
> Some very interesting points so far. To avoid making this email too
> long, I'm going to reply without quoting - I hope this doesn't
> inconvenience anyone.
>
> Regarding the memorability issue, all I can say is that end-to-end
> encryption really does require sharing 100+ bit keys - it's essential!
> You may be able to memorise your email address at the moment, but
> that's only half the story, since you can't memorise your public key!
> I can't solve every problem with PGP, but I still think this proposal
> solves a fair few of them. In some cases it improves on PGP, and in
> the other case it's at least no worse: you can still use online
> institutional directories etc if you want.
>
> Don't forget all the advantages this scheme could bring! Simplicity
> and transparency for the end user is really important! They're more
> likely to understand the significance of a public key if it forms part
> of the address (despite not understanding why it has to be this way).
>
> Perhaps it doesn't help Derek's mum - nor my mum, for that matter -
> but there are plenty of people for whom PGP is to complex whereas this
> scheme would be manageable. If you wish, you can send some emails
> encrypted and others unencrypted, just like you can with PGP - in this
> case, you'd just need two addresses (which is surely no worse than
> PGP, where you have an address and a key).
>
> Regarding telephone conversations: if it's with a mobile phone,
> perhaps a text message would work; if it's a landline, you probably
> have internet access, so an initial unencrypted email would work if
> you're not worried about man-in-the-middle attacks. (If you are
> worried about such attacks, then a bit of effort might be required,
> beyond just rattling off a short email address over the phone.)
>
> By the way, I'm suggesting printable characters to encode the key, not
> arbitrary bytes. An alphanumeric character stores nearly 6 bits (or 5
> if it isn't case-sensitive), so 256-bit keys would require around 50
> characters. Email standards allow 64 characters for the local part of
> the address, so there's room for error-correction too.
>
> Regarding the point about forged email addresses: for cryptography to
> work, you need to identify people using their keys, not their
> addresses. With PGP, you could send an email to my mum, using my email
> address but the wrong signature; if my mum is just relying on the
> email address, then that defeats the purpose of PGP. Of course, most
> PGP systems compare the key with that stored in the address book; a
> similar system can be used for my proposal, but with the advantage
> that forged emails don't give rise to the situation where the address
> is known but the key is unknown, which might lead a naive user to
> assume something's broken with the crypto software.
>
> Regarding webmail... I still haven't solved that one. Maybe there's an
> inherent contradiction in trying to include webmail in an end-to-end
> encryption system.
>
> I like the idea of using the "address+key at gmail.com" technique,
> although it does contradict the idea of "identify people using the
> key, not the address". Also, in my original proposal, I suggested
> using the private key (instead of a password) to login to the email
> server. I reckon Gmail is unlikely to allow that in the near future :)
>
> Best wishes,
>
> Henry
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