Pre-provisioned Key-access Proposal - Privacy Consideration Update

Although I haven't received that much feedback on

   http://webpki.org/papers/PKI/pki-webcrypto.pdf

I have updated the document with a privacy consideration section.

The scheme offers no privacy silver bullet but maybe a "workable solution".

A generic Web Crypto issue seems to be that either you end-up with a standardized "key-picker" (probably pretty difficult to define) which would mark the selected key as usable by the application to use with the Web Crypto API, or you leave this responsibility to the [presumably well-written] application.   The described solution bets on the latter because this is much more flexible and may even turn out to be a prerequisite for market acceptance.  However, this introduces a potential privacy risk, since there's no platform-provided protection against key "misuse".

BTW, I have recently been experimenting with the extension-scheme used by for example Google to access the Android Play-store which is based on stand-alone handlers for unique protocols like "market://".  This is a strong challenger to Web Crypto solutions for pre-provisioned keys.  This scheme also fits quite nicely with the described solution.

-- Anders

Received on Tuesday, 30 October 2012 09:24:50 UTC