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Diffstat (limited to 'archive/2021-09-14-qna-session')
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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/ |