[Cryptography] Any thoughts on Arqit ?

[Michael Nelson]

> > Any thoughts on what they are doing?
>
> ...
> ▪ They mutually authenticate with QuantumCloud
> ▪ QuantumCloud sends a new shared secret down to the endpoints.
> ...
 > I would recommend against this unless there are some thorough publications behind it.

My thoughts exactly. Thanks for the input, and thanks for the link. One could conjecture that it's a symmetric key KDC as you said, with a little quantum spice thrown in at the server, as an alternative to an HSM. If a nice quantum-proof public key system comes along it could look rather clunky. The company seems to have a valuation of a couple of billion $ !

Mike

On Thursday, January 13, 2022, 05:19:13 PM PST, Richard T. Carback III <rick at carback.us> wrote: 

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Someone sent me this company a little while ago as well, they are definitely advertising — It looks like a KDC approach for key agreement of encrypted connections. From their investor deck:

Devices like phones, servers, cars or fighter jets want to communicate securely together:

▪  They both acquire a “bootstrap key” on day one using an Arqit patented method.

▪  They mutually authenticate with QuantumCloudTM.

▪  QuantumCloudTM sends a new shared secret down to the endpoints.

▪  The devices now create a new shared symmetric key.

▪  They use that key inside an AES256 algorithm to securely share information over classical channels.

▪  These keys are computationally secure, zero trust, unlimited group size and optionally one-time use.


Source: https://d1io3yog0oux5.cloudfront.net/_1e4e61ce0e434d68031867e29c03d4e7/arqit/db/2137/19926/pdf/FYE+Earnings+Presentation+vFinal.pdf <https://d1io3yog0oux5.cloudfront.net/_1e4e61ce0e434d68031867e29c03d4e7/arqit/db/2137/19926/pdf/FYE+Earnings+Presentation+vFinal.pdf>

I would recommend against this unless there are some thorough publications behind it...

-R

> On Jan 13, 2022, at 7:38 PM, Michael Nelson via cryptography <cryptography at metzdowd.com> wrote:
>
> Website:  https://arqit.uk <https://arqit.uk/>
>
> Someone asked me about this company. They seem to have made a pretty fancy Web site, claim to have some customers, and "a patent moat of 1,435 patent claims" (!).
>
> He's interested in the "QuantumCloud" product. I could not find any concrete whitepaper or anything. There may be publications on the site or elsewhere, but I gave up after watching a video and poking a bit, and thought I'd ask you guys.
>
> It seems to be about quantum key setup. Only symmetric keys are used as they are more resilient to quantum computing. Seems to include corporate/govt use, and consumer use. My guess is that the former has some quantum stuff at each endpoint, whereas the consumer application has an app on a conventional mobile phone, and the quantum stuff is done on a satellite.
>
> I've no idea how they deal with authenticating the users, so that they know who they are talking to, the usual challenge of quantum key setup.
>
> A few quotes:
>
> "It creates unbreakable, trustless, one time symmetric encryption keys in infinite group keys and with infinite frequency of refresh."
>
> "QuantumCloud puts a lightweight agent at any endpoint device. This software creates an unlimited number of symmetric keys with partner."
>
> "impossible for this ... to be stolen and used ..."
>
> Any thoughts on what they are doing?
>
> Mike



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