CPS-0142? | Light Client Protocols

[cleanerm5]

Hi,

There are a few activities ongoing that require the development of so called light client protocols for Cardano. The ones that came to my awareness are:

• the IBC implementation of CF (https://github.com/cardano-foundation/cardano-ibc-incubator)
• the Bitcoin-Cardano bridge proposed by BitcoinOS and with the general approach described in this paper (https://assets-global.website-files.com/661e3b1622f7c56970b07a4c/662a7a89ce097389c876db57_BitSNARK__Grail.pdf)
• the IOG research work on trust-minimized light client based wallets

There are various ways how to implement light clients on Cardano (whereas because of the core protocol not providing so called state proofs out of the box, there is no canonical light client design available for Cardano at the moment). In that sense, I wanted to create a common point of reference and problem description with this CPS to which concrete light client designs can refer to when they are documented as a CIP.

At least for the IBC implementation we plan to document the Mithril based light client as a CIP and the same would make sense for the respective light client protocol to be developed for a Bitcoin-Cardano bridge (in case the bridge follows a light client based security model), because both designs can be used for other use cases as well.

Any feedback is highly appreciated.

Kind regards

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[rphair]

Thanks, I'm marking Triage to begin discussion of this at the next CIP meeting (https://hackmd.io/@cip-editors/102) if not earlier in this thread.

This will be an introduction of the CPS, rather than a full review, but I would also plan to discuss the scope enough to see if a category of Network rather than Tools would be appropriate. @cleanerm5 you have obviously put a lot of thought into applications so I would hope you can come to this meeting in a week's time to answer this question first.

[rphair]

Confirmed as candidate in CIP meeting today: pending a title revision that reflects not a standard / framework for "light client protocols" but rather a means of incorporating these into the main protocol with proofs (as @colll78 pointed out).

Ordinarily we would wait for a title accurately representing the CIP scope, but given the high profile concurrent work that relates to this CIP we decided to put the number through immediately.

Please @cleanerm5 rename the directory to CIP-0142 and re-link your readable proposal in the first comment. 🎉

[rphair]

@cleanerm5 if you could work with reviewers & editors to make or propose a title change, as per the above comment, it would be appreciated before the end-of-year work hiatus begins.

[colll78]

It is about light client protocols, but not about the networking, it is about the technological properties of light client proofs to verify state transitions on Cardano in contracts on other chains.