[messaging] Do quantum attacks/algos also lead to compromise of PFS?

[Tao Effect]

> Yes.  Shor's algorithm can compute finite field and elliptic curve
> discrete logs, so an attacker who saved a transcript of g^a, g^b over
> the wire today can, if/when quantum computers become available,
> compute a, b, and g^ab and retroactively decrypt the rest of the
> encrypted transcript.

... Shit.

--
Please do not email me anything that you are not comfortable also sharing with the NSA.

On Jan 24, 2015, at 1:18 PM, Taylor R Campbell <campbell+moderncrypto at mumble.net> wrote:

>   Date: Sat, 24 Jan 2015 13:07:29 -0800
>   From: Tao Effect <contact at taoeffect.com>
> 
>   So, I understand that QM algos can pretty much dismantle all
>   popular asymmetric encryption algos with enough q-bits, but I
>   haven't thought hard enough to see if they also can be used to
>   compromise communications that used DH to do PFS underneath the
>   initial handshake.
> 
> Yes.  Shor's algorithm can compute finite field and elliptic curve
> discrete logs, so an attacker who saved a transcript of g^a, g^b over
> the wire today can, if/when quantum computers become available,
> compute a, b, and g^ab and retroactively decrypt the rest of the
> encrypted transcript.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://moderncrypto.org/mail-archive/messaging/attachments/20150124/3f356937/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 841 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <http://moderncrypto.org/mail-archive/messaging/attachments/20150124/3f356937/attachment.sig>