On 8 August 2017 at 18:25, vaibhav singh <vaibhavsinghacads@xxxxxxxxx> wrote: > > > On Tue, Aug 8, 2017 at 8:56 PM, Dave Cridland <dave@xxxxxxxxxxxx> wrote: >> >> On 14 July 2017 at 15:42, Yoav Nir <ynir.ietf@xxxxxxxxx> wrote: >> > While it may be OK to share a key with my phone (but too difficult to do >> > securely in practice), sharing with a delegate is hairy on many >> > different >> > layers. But still it’s the same issue. >> >> I think it's all solvable using Proxy Re[en]cryption, but that seems >> to be a little fraught with patents at the moment. > > > I am not comfortable with sharing my private key with anyone, be it the > proxy user itself. I believe that is a requirement for Proxy Reencryption, > please correct me if I may have interpreted it wrongly. > You have interpreted it incorrectly. The proxy holds a key that will change a message encrypted to its proxy key into a message encrypted for an authorized key. It cannot decrypt the message to plaintext itself. All quite bleeding edge, all quite patent-encumbered, but look at Mathew Green's work for details - he's been researching very heavily in this field. Dave.