diff --git a/paper/ltl.pdf b/paper/ltl.pdf index 019a538..fe869d6 100644 Binary files a/paper/ltl.pdf and b/paper/ltl.pdf differ diff --git a/paper/ltl.tex b/paper/ltl.tex index 0eeca6d..8967112 100755 --- a/paper/ltl.tex +++ b/paper/ltl.tex @@ -47,7 +47,7 @@ showstringspaces=false,breaklines=true,xleftmargin=.5em,xrightmargin=.5em} \large A Transparency Model and the Lean Transparency Log} \author{Olaf Horvath\\ \small Olaf.Horvath@zkdefi.org \quad ORCID 0009-0004-8008-5805} -\date{July 2026 \quad (v0.6)} +\date{July 2026 \quad (v0.7)} \begin{document} \maketitle @@ -297,9 +297,11 @@ does not consume an operator verdict as positive evidence. \begin{definition}[Accountable replay distribution] Fix an operator public key and a consumer that persists accepted signed heads. A replay-distribution scheme is \emph{accountable} if the following hold: -(i) every accepted attestation is position-bound to a signed view; (ii) a +(i) every accepted attestation has a unique accepted opening at its claimed +position under an authentic signed view; (ii) a consumer accepts a later view only as the same view or a verified extension; -(iii) two valid equal-size heads with unequal roots form transferable evidence +(iii) two valid equal-size heads with unequal roots, in one log and protocol +context, form transferable evidence that the key holder signed incompatible views; and (iv) positive acceptance of a theorem boundary is a function of recorded observations and consumer-local policy, not of an operator verdict. @@ -558,8 +560,9 @@ the iterative verifier does when size claims alone steer its walk. Assume EUF-CMA security of the head signature and collision resistance of SHA-256. A consumer following the pin transition accepts only a nondecreasing sequence of sizes whose exhibited leaf lists are prefix-related. Two accepted -heads under the same key with equal size and unequal roots are transferable -evidence that the key holder signed incompatible views. +heads under the same key, in one log context, with equal size and unequal +roots are transferable evidence that the key holder signed incompatible +views. \end{proposition} \begin{proof} Rollback is rejected syntactically. At equal size the transition is accepted @@ -567,8 +570,9 @@ only with equal roots; if the two exhibited equal-length leaf lists differed, whole-tree binding would extract a SHA-256 collision, so under collision resistance the lists are equal. A larger head is accepted only after a consistency proof, so non-prefix acceptance yields a collision by the previous -theorem. Equal-size unequal roots with valid signatures are two conflicting -statements attributable to the key holder, except under signature forgery. +theorem. Equal-size unequal roots in one log context, with valid signatures, are two +conflicting statements attributable to the key holder, except under signature +forgery. \end{proof} \begin{proposition}[Policy separation] @@ -606,24 +610,30 @@ unmechanized authentic-size/root invariant. \subsection{Scheme-level games and a composition theorem}\label{sec:games} The theorems above bind single artifacts to a reference leaf list. This -subsection lifts them to the scheme. Fix once, for the entire subsection, a -\emph{context} -\[\chi=(\text{log identifier},\ \text{schema and type tags},\ -\text{hash-algorithm identifier},\ pk);\] -every head below is required to encode $\chi$ in its canonical payload, -matching the deployed head format of \S4.2. +subsection lifts them to the scheme. Fix once, for the entire subsection, an +\emph{encoded context} +\[\chi_{\rm enc}=(\text{log identifier},\ \text{schema and type tags},\ +\text{hash-algorithm identifier});\] +every head below is required to encode $\chi_{\rm enc}$ in its canonical +payload, matching the deployed head format of \S4.2. The verification key is +deliberately \emph{not} part of the payload: it is an external verification +parameter, and we write $\chi=(\chi_{\rm enc},pk)$ for the full context once +a key exists --- the keyed games below fix $\chi_{\rm enc}$, run +$\mathsf{KeyGen}$, and then set $\chi$. The results come in two deliberately separated levels. First, \emph{collision-extractable accountability}: unconditional theorems whose proofs are explicit algorithms turning any winning transcript into a concrete SHA-256 collision, and reductions whose signature losses are exactly one EUF-CMA forgery. Second, a \emph{security corollary}: SHA-256 is a fixed, unkeyed function, so collision resistance cannot be a probability statement -over a key space; following the human-ignorance treatment~\cite{rogaway}, the -hardness premise is that no feasible collision finder for SHA-256 is known, -and the corollary states what the explicit reductions then rule out. (A +over a key space; following the human-ignorance treatment~\cite{rogaway}, the hardness +premise --- that no feasible SHA-256 collision finder is known --- is an +epistemic engineering judgment, and the corollary states only the +constructive consequence: an explicit winner yields an explicit collision +finder. (A keyed-family restatement is routine and omitted.) Extractability does not by -itself assert hardness; the corollary is where hardness enters, and only -there. +itself assert hardness; the corollary's explicitly labeled interpretation +sentence is where the judgment enters, and only there. The position-binding and history games are non-interactive, and the right reason is not merely that the operator-adversary holds the signing key: the @@ -639,7 +649,7 @@ wins. \paragraph{Accepted-artifact syntax.} A head is $h=(n,r,t;\sigma)$, with $t$ a timestamp; its canonical payload is -$\mathsf{EncodeHead}_\chi(n,r,t)$ as in \S4.2, and $\mathsf{Vf}_{pk}(h)=1$ +$\mathsf{EncodeHead}_{\chi_{\rm enc}}(n,r,t)$ as in \S4.2, and $\mathsf{Vf}_{pk}(h)=1$ iff its Ed25519 signature verifies. An \emph{opening} of leaf $d$ at index $m$ under $(n,r)$ is a path $P$ with $m (The full walk-through is lecture 11 in the

The paper

Accountable Distribution of Machine-Checked Correctness Evidence: A Transparency Model and the Lean Transparency Log -(PDF, 21 pages, v0.6) — the trust decomposition (expensive verification produces an +(PDF, 21 pages, v0.7) — the trust decomposition (expensive verification produces an observation; transparency makes the observation accountable; consumer-local policy decides acceptance), collision-extracting soundness for inclusion and consistency, scheme-level accountability GAMES with an explicit composition theorem (head authenticity, position