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[Notes] SessionLatch: Attested TLS for Confidential Virtual Machines

Last updated Attestable Computing Papers

Paper

While TLS authenticates a service identity and attestation tells you an environment is approved, clients can’t be certain that the TLS session actually in use terminates in the expected environment. SessionLatch proposes using a trusted observer inside CVMs to prove session-endpoint correspondence.

This observer produces TEE-bound evidence which clients can fetch via a separate control channel as the handshake proceeds, holding (latching) client encrypted records until the evidence verifies and frees up the data path.

The Linux implementation relies on a userspace observer using SOCK_DIAG, nftables/NFQUEUE and other OS facilities. A measured/enforced eBPF or similar kernel mechanism could potentially provide a stronger reference monitor and bind the session to richer workload identity.

More broadly, the paper illustrates why endpoint attestation becomes harder as the TEE boundary expands from process enclaves to entire confidential VMs.

[Notes] Agent Security Is a Systems Problem

Last updated Agent Runtime Security Papers

I recently went over two articles from March-May 2026 that highlight how alignment can improve an agent’s behavior, but security must hold even when the model makes the wrong decision. I found these reads valuable grounding for thinking about agent architectures.

Perplexity’s Security Considerations for Artificial Intelligence Agents develops a layered defense strategy; Christodorescu et al.’s Agent Security Is a Systems Problem treat the model as untrusted and enforce security invariants outside it.

The latter posits the model’s learned judgment should not be part of the TCB, because the model is inherently probabilistic, and we can’t have a probabilistic TCB. A boundary that holds only when the model correctly interprets an instruction or recognizes an attack is a behavioral expectation, not an enforceable restriction.

The papers identify concrete open research problems, including verifiable policy generation: translating a user’s evolving natural-language intent into enforceable constraints. Moving enforcement outside the model is necessary, but letting the same untrusted model freely define its own policy would recreate the original dependency.

Taking the untrusted-model assumption seriously changes how we design agents. A model-generated tool call is a request for authority, not proof of authorization. These requirements become harder when the workflow itself emerges at runtime, rather than following a program whose resource needs are known in advance. There are excellent analogies in here for people working on code integrity, particularly dynamic/JITted code security.

Related designs explore how to enforce these boundaries: aflock places authorization and evidence generation in an external MCP server, while Grimlock uses eBPF-mediated sandbox boundaries and attested channels to enforce identity and constrain delegation outside agent code.

[Notes] AIBoMGen: Generating an AI Bill of Materials for Secure, Transparent, and Compliant Model Training

Last updated Software supply chain security Papers

In AIBoMGen: Generating an AI Bill of Materials for Secure, Transparent, and Compliant Model Training, a controlled training platform observes datasets, configuration, environment, and artifacts as the job executes, then hashes the artifacts and produces signed AIBOM and in-toto evidence.

AIBoMGen makes that possible by restricting the training environment. Users provide inputs and parameters rather than arbitrary code or shell access, allowing the platform to remain an independent observer of a constrained workflow. This limits generality and leaves trust in the platform, workers, signing keys, containers, and cloud control plane, but demonstrates a broader principle: trustworthy provenance may require constraining execution enough that evidence generation cannot simply be bypassed.

For a related approach to authenticating ML transformation history with hardware-backed attestation and transparency logs, see my notes on Atlas.

[Notes] Practical Post-Quantum Cryptography for Bandwidth Constrained or Non-Terrestrial Networks, and Power Constrained Devices

Last updated Cryptography Papers

The core takeaway is that many systems already have a shared secret anchored in trusted hardware, such as a SIM or TPM, and infrastructure that already knows how to derive and manage keys from it.

The authors propose reusing that existing trust: derive an application-specific secret, make it available through a KDC and trusted transfer agent, use it for TLS or DTLS PSK authentication—otherwise the dominant source of resource consumption and handshake unreliability—and keep ML-KEM for ephemeral post-quantum key establishment and forward secrecy.

This avoids dragging large post-quantum certificates and signatures across constrained devices and lossy links. The authors observed about 70% less handshake bandwidth and roughly one-third the energy consumption. The broader takeaway is that, in some scenarios, post-quantum readiness may not require rebuilding the authentication stack if the system already has a scalable symmetric root of trust.

Read the paper on arXiv. And for a related look at reducing PKI overhead on constrained devices, see my notes on lightweight certificate revocation for low-power IoT.

[Notes] Trusting-Trust Attack against an Entire Linux Distribution through Binary Manipulation

Last updated Papers Software supply chain security

The paper shows how Thompson-class attacks aren’t restricted to compilers by tampering with strip in the NixOS bootstrap seed. The malicious strip repurposes PT_NOTE as PT_LOAD, and the payload propagates into later generations of strip rebuilt from clean source. All but one binary in stdenv ends up infected, without breaking the build or functional tests.

I walked away thinking about diverse artifact structure verification: population-level artifact checks run from independent trust roots, with independently built parsers and tooling. Could we come up with a stable ELF morphology of a distribution and use that to detect a coordinated structural shift across thousands of unrelated binaries?

For a related approach to detecting compiler subversion, see my notes on Rosencrantz’s Diverse Double-Compiling (DDC), including the challenges of extending verification across a real build graph.

Really good read by Julien Malka, Stefano Zacchiroli, Martin Monperrus, and their coauthors: read the July 2026 paper on arXiv.

[Book review] Hack to the Future

Last updated Books Cybersecurity Canon

Emily Crose’s Hack to the Future: How World Governments Relentlessly Pursue and Domesticate Hackers traces hacker culture from exploratory experimentation to a foundational role in modern cybersecurity. It examines how governments, corporations, and society shifted from treating hackers primarily as criminals to recognizing their value in security, innovation, and national strategy.

The book provides useful context for understanding the origins of penetration testing, vulnerability research, responsible disclosure, and the complicated relationship between independent researchers and institutions.

Read my full review on the Cybersecurity Canon.

[Notes] The End of Code Review: Coding Agents Supersede Human Inspection

Last updated Software supply chain security Papers

The core argument is that coding agents have crossed the threshold where mandatory human code review is no longer economically justified. Human review consumes an estimated 10–15% of developer time, and scaling code generation while keeping humans as the approval gate simply moves the bottleneck downstream.

Readers might find the implication for SCM architecture most interesting. GitHub/GitLab-like platforms may need first-class agent identities, cryptographically attributable actions, specialized permissions, structured findings and confidence, and machine-readable review artifacts—not agents impersonating humans through comment threads. Agent review also seems better described as auditable and replayable than deterministic.

This suggests code review may evolve from a human synchronization gate into continuous agentic assurance, with human inspection becoming a risk-based escalation path in some scenarios.

Link to paper.

[Notes] Fine-Grained Traceability for Transparent ML Pipelines

Last updated Software supply chain security

Fine-Grained Traceability for Transparent ML Pipelines (Chen, Liu, Fayek)

The key idea in FG-Trac is the distinction between explainability and operational traceability. Influence methods such as TracInCP can retrospectively estimate how training samples affect predictions, but they do not establish when, where, and under which model state those samples actually participated. FG-Trac instruments the ML pipeline itself, recording sample lifecycle events and binding checkpoint-based influence scores to those events.

These records are committed through Merkle trees, with detailed encrypted logs kept off-chain and only constant-sized roots anchored on-chain. This lets a user trace a pseudonymous sample through training, inspect its positive or negative influence, and cryptographically verify that the resulting history has not been modified.

The important limitation is that the commitment proves integrity of the recorded history, not completeness or truthfulness of its creation; a malicious operator could bypass instrumentation before commitment. Hardware-backed attestation or TEEs could strengthen that boundary.

For a related approach combining hardware-backed attestation and transparency logs to authenticate ML transformation history, see my notes on Atlas.

[Notes] Grimlock: Guarding High-Agency Systems with eBPF and Attested Channels

Last updated Attestable Computing Agent Runtime Security Papers

The core idea in Grimlock is separation of concerns for high-agency systems: agent code handles orchestration, while the sandbox substrate enforces identity, authentication, authorization, provenance, and least-privilege delegation. Much of this is established security architecture; what I found interesting is how the pieces are composed while leaving agent code unchanged.

eBPF provides no-bypass, application-transparent mediation at the sandbox boundary and associates ordinary socket flows with stable sandbox identities. Guard-to-guard communication uses TLS 1.3 with kTLS for the data plane, allowing authentication context and longer-lived channels to amortize setup costs.

Post-handshake attestation is of special note. TLS exporters bind fresh TEE evidence to an already-established channel, including nonce, audience, and requested delegation scope. Successful appraisal produces short-lived, channel-bound Scope Tokens that the destination guard revalidates before releasing plaintext to the destination sandbox.