[messaging] Signal Protocol Licensing/Intellectual Property Status

Nadim Kobeissi nadim at nadim.computer
Fri May 6 10:12:59 PDT 2016

Hi Torsten,
Unfortunately, the description you link to does not satisfy my question because it does not describe the full signal protocol. It is lacking, at least:

1. A description of the four-way Diffie-Hellman handshake (or any authenticated key exchange at all),
2. The involvement of the short-term signed pre-key in addition to the one-time-use pre-key.


From: Messaging <messaging-bounces at moderncrypto.org> on behalf of Torsten Grote <t at grobox.de>
Sent: Friday, May 6, 2016 7:04:05 PM
To: messaging at moderncrypto.org
Subject: Re: [messaging] Signal Protocol Licensing/Intellectual Property        Status

On Friday, May 06, 2016 04:49:44 PM Nadim Kobeissi wrote:
> Are the protocols and algorithms all in public domain

According to the page [1] where the protocol was described initially, yes:

> The Double Ratchet specification (this wiki) is hereby placed in the public
> domain.

Kind Regards,

[1] https://github.com/trevp/double_ratchet/wiki#ipr

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