google · taknira · Sep 4, 2026 · Sep 4, 2026
@@ -15,26 +15,50 @@ <h1 class="headline2 sm:text-center gmb-4">
         <tbody>
           <tr class="border-b border-gray-200 dark:border-gray-700">
             <td class="px-6 py-3">
-              Matthew McPherrin
+              Ben Birt
             </td>
             <td class="px-6 py-3">
-              <a href="/summit2026/talks/le-mtcs.html">How Let's Encrypt is deploying Merkle Tree Certificates</a>
+              <a href="/summit2026/talks/git-ratchet">⚡ Git-ratchet: tooling for Git commit transparency</a>
             </td>
           </tr>
           <tr class="border-b border-gray-200 dark:border-gray-700">
             <td class="px-6 py-3">
               Hayden Blauzvern
             </td>
             <td class="px-6 py-3">
-              <a href="/summit2026/talks/sigstore.html">Simplicity through Transparency: How the PQC Migration is Streamlining Sigstore</a>
+              <a href="/summit2026/talks/sigstore">Simplicity through Transparency: How the PQC Migration is Streamlining Sigstore</a>
             </td>
           </tr>
           <tr class="border-b border-gray-200 dark:border-gray-700">
             <td class="px-6 py-3">
-              Ben Birt
+              Matthieu Daumas
+            </td>
+            <td class="px-6 py-3">
+              <a href="/summit2026/talks/archive">⚡ Archive Transparency</a>
+            </td>
+          </tr>
+          <tr class="border-b border-gray-200 dark:border-gray-700">
+            <td class="px-6 py-3">
+              Billy Lau
+            </td>
+            <td class="px-6 py-3">
+              <a href="/summit2026/talks/sostenuto">Sostenuto: Scaling & Sustaining Android Binary Transparency</a>
+            </td>
+          </tr>
+          <tr class="border-b border-gray-200 dark:border-gray-700">
+            <td class="px-6 py-3">
+              Matthew McPherrin
+            </td>
+            <td class="px-6 py-3">
+              <a href="/summit2026/talks/le-mtcs">How Let's Encrypt is deploying Merkle Tree Certificates</a>
+            </td>
+          </tr>
+          <tr class="border-b border-gray-200 dark:border-gray-700">
+            <td class="px-6 py-3">
+              Niels Möller
             </td>
             <td class="px-6 py-3">
-              <a href="/summit2026/talks/git-ratchet.html">Git-ratchet: tooling for Git commit transparency</a>
+              <a href="/summit2026/talks/tkey">The TKey sign-if-logged tool</a>
             </td>
           </tr>
         </tbody>

@@ -0,0 +1,38 @@
+---
+url: summit2026/talks/archive
+layout: summittalk
+title: "Archive Transparency"
+topImage:
+type: lightning
+room:
+start:
+speaker: Matthieu Daumas
+speakerTitle:
+---
+
+<div class="font-google font-medium">
+
+Everyday online resources move, change, or disappear, making users rely
+on third-party repositories to keep the past available for them. The
+good reputation of these repositories makes them attractive targets for
+quiet tampering by attackers. This threatens trust in the authenticity
+of historical records, especially in an era of mechanized intelligence.
+
+This talk will introduce Archive Transparency, a prototype that
+explores how transparency logs, Sigsum, and the witness network can
+solve this issue by establishing that a third-party repository content
+has remained unchanged over a long time. This talk will conclude with
+data from a small-scale deployment.
+
+---
+
+### Speaker
+
+Matthieu Daumas is a software engineer based in Berlin, Germany, with a
+background in compile-time cryptography and obfuscating compilers.
+Since 2024, he has been developing Archive Transparency, an open-source
+prototype exploring transparency logs for archival integrity. He is
+actively seeking collaborations and opportunities to help build
+resilient trust infrastructure for digital preservation.
+
+</div>
@@ -1,9 +1,9 @@
 ---
-url: summit2026/talks/git-ratchet.html
+url: summit2026/talks/git-ratchet
 layout: summittalk
 title: "Git-ratchet: tooling for Git commit transparency"
 topImage:
-type:
+type: lightning
 room:
 start:
 speaker: Ben Birt

@@ -1,5 +1,5 @@
 ---
-url: summit2026/talks/le-mtcs.html
+url: summit2026/talks/le-mtcs
 layout: summittalk
 title: "How Let's Encrypt is deploying Merkle Tree Certificates"
 topImage:

@@ -1,5 +1,5 @@
 ---
-url: summit2026/talks/sigstore.html
+url: summit2026/talks/sigstore
 layout: summittalk
 title: "Simplicity through Transparency: How the PQC Migration is Streamlining Sigstore"
 topImage:

@@ -0,0 +1,86 @@
+---
+url: summit2026/talks/sostenuto
+layout: summittalk
+title: "Sostenuto: Scaling & Sustaining Android Binary Transparency"
+topImage:
+type:
+room:
+start:
+speaker: Billy Lau
+speakerTitle:
+---
+
+<div class="font-google font-medium">
+
+Since its inception, Android Binary Transparency (ABT) has served as a
+foundational security primitive for the Android ecosystem. While our effort
+began by tackling transparency at the firmware level (characterized by
+low-cadence monolithic OS builds and manually curated log entries),
+extending these guarantees to the application layer (building on our
+previous work presented in [Crescendo](https://www.youtube.com/watch?v=TZMspOgnr_A))
+introduces distinct onerational requirements, such as high-volume input
+processing and data integrity. Unlike OS images, apps have continuous release
+cadences, multi-variant delivery formats, and widespread deployment footprints.
+
+In this talk, we discuss [Google Product Application Transparency](https://developers.google.com/android/binary_transparency/google_apk/overview)
+(GPAT) and [Android Mainline Modules Transparency](https://developers.google.com/android/binary_transparency/mainline_modules/overview)
+(modular OS components delivered via app update channels), extending
+cryptographic transparency guarantees to standalone product applications
+and OS modules. Logging continuous-release applications such as Google Play
+Services (com.google.android.gms) and YouTube (com.google.android.youtube)
+differs substantially from firmware logging: release cadences shift from
+monthly to continuous, and binary releases involve multidimensional variant
+matrices (varying across ABIs, screen densities, and dynamic feature
+splits). Consequently, a single logical version does not yield a single
+binary hash; it produces a combinatorial explosion of split binaries that
+must all be mapped, deduplicated, and verified without corrupting the log's
+state.
+
+To address these requirements, we designed and built TLUaaS (Transparency
+Log Updater as a Service), a backend ingestion and orchestration pipeline
+engineered for large-scale log writing. We will discuss the design
+decisions, failure modes, and operational lessons learned from running
+TLUaaS in production, including:
+
+- Variant Resolution and Pre-Ingestion Deduplication: How TLUaaS computes
+document deltas across continuous release streams, resolves multi-APK
+variant sets, and deterministically normalizes binaries before committing
+irreversible writes to the log.
+- Production Safeguards and Ingestion Containment: Managing ingestion
+pipelines where source metadata (including app signing keys, true release
+manifests, and distribution streams) only exists in production environments
+restricts our ability to perform pre-production testing. Because synthetic
+data cannot account for real-world production variability, we will cover
+the operational safeguards developed to mitigate bad-data ingestion, such
+as emergency containment fail-safes for test packages and strict
+server-targeting controls.
+
+To illustrate end-to-end verification, we will demonstrate [Uraniborg](https://github.com/android/android-binary-transparency/tree/main/uraniborg),
+an open-source audit tool used to scan on-device APKs and verify them
+against published transparency logs and cryptographic proofs. Attendees
+will leave with practical design patterns for operating immutable
+transparency logs that take input from multiple pipelines at scale,
+techniques for handling variant-heavy release pipelines, and strategies for
+maintaining data integrity in supply-chain verification systems.
+
+---
+
+### Speaker
+
+Billy Lau is a security engineer in the Android Security team. He is
+primarily interested in information security, with emphasis on operating
+systems and user applications. In recent years, he has been trying to
+leverage transparency constructs into the Android OS and influence the
+larger ecosystem for the further protection of users. He has been examining
+various security designs for mobile devices and analyzing the security and
+privacy impacts of mobile computing devices in everyday life. He
+particularly loves to challenge the status quo on conventional security
+assumptions, which are often broken when put to test. He aspires to push
+the scientific envelope in mobile security and to make Android the most
+secure consumer operating system by identifying and solving the deepest
+problems in the realm of mobile security and leveraging his position in the
+industry to make mobile computing more reliable and secure. In general, he
+hopes to make a difference by making usable computer systems more secure
+and secure systems more usable.
+
+</div>
@@ -0,0 +1,67 @@
+---
+url: summit2026/talks/tkey
+layout: summittalk
+title: "The TKey sign-if-logged tool"
+topImage:
+type:
+room:
+start:
+speaker: Niels Möller
+speakerTitle:
+---
+
+<div class="font-google font-medium">
+
+The Sigsum transparency system enables detection of unexpected or
+malicious use of a signing key. The owner of a signing key submits
+each signature made to a Sigsum log, and gets back a corresponding
+Sigsum proof of logging. The parties that rely on these signatures
+(e.g., for installing signed software updates) are expected to reject
+any signature that does not come with a valid proof of logging. The
+key owner can then monitor the log and discover all signatures made
+that are going to be accepted.
+
+Discoverability of signatures is a desirable property, but what if you
+are making signatures in a context where those relying on your
+signatures are unable to process a Sigsum proof? E.g., the signature
+may have to follow some standard that's not easily extended with a
+Sigsum proof, or the signatures have to be verified on a slow embedded
+system where extended verification is impractical for performance
+reasons.
+
+The Tillitis TKey is an open source USB hardware security device which
+allows running small arbitrary applications in a more secure
+environment, using measured boot to give each application its own
+secret. Security keys and HSMs, including the TKey, are often used as
+signing oracles. But we can do better, by having the device also
+enforce Sigsum logging of the data before signing.
+
+The sign-if-logged tool consists of a host program, and a TKey device
+app. The host program configures the device app with a Sigsum policy
+and a list of authorized submitter keys. The host program can then ask
+the device to sign data, but the device requires that the host also
+provides a Sigsum proof, valid according to its configuration.
+
+This way, the signing party gets discoverability of signatures, and
+the ability to detect unexpected or malicious key usage, without the
+parties relying on those signatures having to know about it.
+
+The talk will give a brief introduction to Sigsum and the TKey
+hardware. It will explain how the sign-if-logged tool works and how to
+use it. If time permits, it will also introduce the Sigsum C library,
+which is designed with constrained embedded systems in mind.
+
+A version 1.0.0 of the sign-if-logged tool was released this summer.
+
+Source code and documentation:
+https://git.glasklar.is/sigsum/apps/sign-if-logged
+
+---
+
+### Speaker
+
+Working with the Sigsum project at Glasklar Teknik since 2022. Main
+author and maintainer of the GNU Nettle crypto library. PhD from the
+Automatic Control group at KTH.
+
+</div>