W3C home > Mailing lists > Public > public-credentials@w3.org > September 2022

Seeking Parters for CSR (Collaborative Seed Recovery) of Identities

From: Christopher Allen <ChristopherA@lifewithalacrity.com>
Date: Mon, 12 Sep 2022 15:11:17 -0700
Message-ID: <CACrqygBz+AQGErdxWRBJsFPJDzR6-n1FyJ9EufZBCdYWX2oKTQ@mail.gmail.com>
To: Credentials Community Group <public-credentials@w3.org>
Blockchain Commons has recently begun work on a new architecture called
Collaborative Seed Recovery, or CSR, intended to improve the resilience of
cryptographic seeds used for digital assets and digital identity. We are
actively working with multiple partners, ranging from wallet software
developers, hardware manufacturers, and silicon chip designers, to release
our first public implementations late this fall.

The idea behind CSR is to make it easy to recover cryptographic seeds in an
automated way. This is done primarily through Shamir’s Secret Sharing and
our security-reviewed `bc-sskr` library.

SSKR allows us to shard a secret in and then send shares to other parties,
but our scenarios allow for many different scenarios ranging from simple "2
of 3" quorum, to more complex scenarios with multiple sub-groups, such as
"two of three of three 2 of 3s", which is useful for several anti-collusion
scenarios (for some more detail see

However, we want to go beyond solely specifying a cryptographic format for
sharding (such as those used by some early social-key recovery systems that
leverage friends and family members). Instead, with CSR we are focused on
storing your shares in places that are more likely to be accessible for the
long term because they are your trusted partners or are incentivized to
properly be a steward for your shares.

For instead, one share might thus be stored in the cloud platform of the
device you’re using, and the other shares are sent out, potentially to
offline archives or friends or family, but most likely to “Share Servers”
who exist primarily to store shares for you. We already have two wallet
vendors committed to offering seed recovery services for each other's
customers, and several others considering doing so.

Given this is an ecosystem design, our requirements must also include
things like defining APIs to re-establish secure authentication between
parties after a major failure, not a common design requirement elsewhere.
Other challenges are securely storing additional recovery metadata, such as
VCs, NFTs, descriptors, etc., as well as future-proofing for emerging
technologies like musig, FROST, and new zk technologies that allow
for distributed key generation & management.

We’ve written a document that includes more details on CSR 1.0:

We also have some video archives of our recent CSR-related presentations
and meetings in a YouTube playlist at

We are looking for an identity vendor, in particular an issuer of
credentials, to come on board as a sustaining sponsor to join with digital
assets and hardware companies that we already have working on the design.
Our goal is to ensure that digital identity gets an equal voice in this
architecture, allowing it to be even more helpful for our community as a

If you’re interested in more information, or if you’re already ready to
join up and take part in our bi-weekly calls developing this architecture
(to restart after RWOT11), please chat me up at RWOT11 in the Hague, or
send me an email.

-- Christopher Allen
Received on Monday, 12 September 2022 22:12:07 UTC

This archive was generated by hypermail 2.4.0 : Monday, 12 September 2022 22:12:08 UTC