From 0eeb567adf2cdb7396f3a4448c06799a485a89e9 Mon Sep 17 00:00:00 2001 From: Rasmus Dahlberg Date: Tue, 14 Sep 2021 21:29:03 +0200 Subject: persisted pads from meeting minutes --- archive/2021-09-14-checkpoint-format-summary | 18 ++++++++++ archive/2021-09-14-qna-session | 50 ++++++++++++++++++++++++++++ 2 files changed, 68 insertions(+) create mode 100644 archive/2021-09-14-checkpoint-format-summary create mode 100644 archive/2021-09-14-qna-session (limited to 'archive') diff --git a/archive/2021-09-14-checkpoint-format-summary b/archive/2021-09-14-checkpoint-format-summary new file mode 100644 index 0000000..f41b8c9 --- /dev/null +++ b/archive/2021-09-14-checkpoint-format-summary @@ -0,0 +1,18 @@ +Decision about checkpoint format? + * First line is a free form unique log ID + * Leave everything else as is + * If anyone wants Verifier("Property X") from witnessing -> use [otherdata] + * Leave [otherdata] undefined for now, focus on Verifier("Append-Only") + * Possible documentation TODOs + * Warning: monitors need to ensure that they have fresh append-only views. The base witnessing format helps with append-only, not freshness. + * Warning: if you plan for witnesses to peek into [otherdata], it would probably be a good idea to propose a common format that will facilitate such witnessing. + +Way forward in sigsum? + * Easiest thing right now is to just add checkpoint as an endpoint and keep everything else as is. This should work well with TrustFabric's Feeder/Distributor thoughts. + * Motivation + * Don't have to figure out [otherdata] exactly right now "in a rush" + * Others can add their opinion and discuss what [otherdata] should (not) be + * We can do a proper trial-run of the design that we have and learn from it + +What do we do now with sigsum x trustfabric? + * Homework until next time to think about this? diff --git a/archive/2021-09-14-qna-session b/archive/2021-09-14-qna-session new file mode 100644 index 0000000..e57cdf8 --- /dev/null +++ b/archive/2021-09-14-qna-session @@ -0,0 +1,50 @@ +Q/A session rgdd-rohon + +Q: how sigsum project different than ct from security / architecture point of view + +CT + * SCTS, promises of public logging + * Centrally trust the logs because it is difficult to audit in practise + * Privacy + * Complexity + +Sigsum + * No SCTs, you need to fetch an inclusion proof that references a cosigned tree head + * Decentralized/distributed trust, assumption is an honest majority for witnesses + * A pretty opinionated gossip-audit model, much emphasis on simple and minimalistic + +Q: why no cryptographic agility / what is the motivation? + * Don't let people use old bad choices like rsa, legacy tools, etc. + * Makes exchanged protocol messages simpler (e.g., no negotiation) + * Makes supporting sigsum protocol easier (you need one primitive, not many) + * If a primitive breaks -> roll up protocol version + +Q: Elaborate about "the right data"? + * Suppose you downloaded Tor Browser + * Signature is valid + * Now what? + * You kind of have to trust that the signer signed the right data + * What if the signer was coereced to sign a back-doored version? + * What if the signing key was stolen? How would a signer even detect that? + * Sigsum logs add discoverability into signing operations + * Anyone can detect what has been signed by monitoring sigsum logs + * "Oh, there is this signature that doesn't correspond to any Tor Browser Bundle" + * "Tor Project, what is that? Please look into this issue and explain" + * This type of transparency is difficult without a log that adds discoverability + +Q: What crypto primitives are supported + * Ed25519 (signify, minisign, etc.) + * SHA256 + * (Remark: we are thinking about Ed25519ph and SHA512/256) + +Q: At what part Rohon comes in? + * Model system formally, requires notation + * Think about how security proof goes (properties, assumptions, argument) + +Some links + * Claimant model + * https://github.com/google/trillian/blob/master/docs/claimantmodel/CoreModel.md + * Sigstore (good to be aware of, does similar things with different trade-offs) + * https://www.linuxfoundation.org/en/press-release/linux-foundation-announces-free-sigstore-signing-service-to-confirm-origin-and-authenticity-of-software/ + * https://www.sigstore.dev/ + * https://github.com/sigstore/rekor/ -- cgit v1.2.3