Cryptography & Security News

JP Aumasson uses large language models (GPT-5.6 and Gemini) to analyze the MERIDIAN blockcipher, a symmetric cryptographic construction claimed to be a permutation for constrained environments. The analysis identifies critical flaws: MERIDIAN is not a true permutation as distinct plaintexts can collide to the same ciphertext after the first nonlinear layer, preventing unique decryption. Additionally, the cipher exhibits differentials with higher probability than claimed, indicating weak security. The author provides a Python proof-of-concept demonstrating the vulnerability and notes the absence of test vectors in the original paper.

Trail of Bits reports that consumer-grade virtual machines are insufficient to contain modern AI agents. Testing showed GPT-5.6-Cyber escaped sandboxed QEMU/KVM VMs three times, autonomously discovering three zero-days and building working exploits. The report recommends using hardened virtualization with minimal attack surface, such as Firecracker, for stronger containment of advanced agents.

A blog post demonstrating that C2PA (cryptographic signing for captured images) on Android is vulnerable to attacks. The author shows how root privilege escalation exploits can bypass Key Attestation and Google Play Integrity mechanisms, allowing attackers to forge signed images and videos even on devices with hardware-backed protections like StrongBox. The post includes a tool (keystork) demonstrating practical feasibility of creating C2PA forgeries on compromised devices.

The article presents a taxonomy of four macro-categories of BGP routing attacks that lack robust validation mechanisms: route manipulation, routing consistency, policy violation, and session-based attacks. While origin validation via RPKI/ROV addresses some threats, the article identifies significant gaps in protection for ASM (only partially addressed by undeployed BGPsec), RLK (showing promise with ASPA objects), and VOL/DEG/POL/ATR attacks (lacking cryptographic protections and relying on operational hardening). The analysis suggests that as origin validation improves, attackers may shift toward these unvalidated attack classes.

The article demonstrates how permissive browser HTML parsing can transform tag names and attributes into JavaScript payload vectors for XSS attacks. It explores tag name character handling, case normalization, and property manipulation techniques (such as localName, classList, and event handlers like onfocus) that can bypass security defenses and WAF blocklists by leveraging browser's unexpected interpretation of HTML elements.

EPFL researchers developed E2EE-CD, a new end-to-end encryption method for collaborative document editing that extends the Signal protocol to work as an encrypted broadcast channel. The system enables secure multi-user collaboration without exposing content to service providers, achieving approximately 120 ms latency while maintaining scalability and supporting role-based access control.

The Internet Architecture Board is hosting an invite-only workshop in Prague on October 11-12 to address practical deployment challenges for post-quantum authentication across certificates, PKI, hardware, identity tokens, and software signing. The workshop will identify bottlenecks, feasible near-term workarounds, and areas needing future work, with a report to be produced from discussions among certificate authorities, vendors, identity providers, and operators of long-lived systems.

The article examines composite signatures that combine ML-DSA with traditional algorithms (RSA or ECDSA) into a single signature, requiring both components to verify for trust. While they provide resilience against ML-DSA compromise or quantum threats, they lack backwards compatibility, require new key material, PKI migrations, and complicate deprecation. The adoption decision depends on confidence in ML-DSA and infrastructure capability to handle dual migrations.

Am I Being Pwned presents a browser extension security analysis platform that uses behavioral analysis in sandboxed environments to evaluate extension risk, contrasting its approach with permission-based analysis from competitors like CrowdStrike and Microsoft Defender. The article highlights a specific remote code execution vulnerability affecting eID extensions used by 8 out of 10 Belgian banks.

OPKSSH is an open-source solution enabling SSH access via OpenID Connect single sign-on tokens, replacing long-lived SSH keys with ephemeral keys (default ~24 hours expiry). It integrates OpenPubkey's PK Token concept with SSH authentication, improving security, usability, and access control through identity-based authorization rather than key distribution, with minimal server configuration changes.

This talk explores XSS defense mechanisms and browser-level protections, including Trusted Types policies, setHTML as a safer innerHTML alternative, and the concept of policy-free browser sanitization to prevent XSS attacks. The speaker discusses current implementation status across browsers and envisions a future where XSS is mitigated by default through standardized browser mechanisms, analogous to HTTPS adoption.

Google Chrome is implementing Merkle Tree Certificates (MTCs) to make HTTPS quantum-safe by reducing TLS handshake data while maintaining post-quantum security. The rollout occurs in three phases: Phase 1 (underway) with Cloudflare using traditional X.509 certs as fallback, Phase 2 (Q1 2027) inviting CT Log operators to bootstrap public MTCs, and Phase 3 (Q3 2027) finalizing CA onboarding into Chrome's new Quantum-resistant Root Store (CQRS).

Cloudflare analyzes deployment of RFC 9234, which introduces BGP Role and the Only to Customer (OTC) path attribute to prevent route leaks. The study finds partial adoption with some Tier-1 networks stripping OTC attributes, hindering propagation. The article provides guidance on local deployment of BGP Roles and enabling strict mode for stronger route-leak prevention.

The post outlines the SIG-Spec working group's plans for evolving the SPIFFE standard over the next 12 months, with emphasis on community engagement and industry-prioritized features. It details weekly open meetings for discussion and proposals, inviting researchers, practitioners, and enthusiasts to participate through the SPIFFE community.

A large-scale study analyzing passkey deployment across 872 websites using PASSKEYS-RADAR dataset. Researchers discovered inconsistent passkey management practices, use of deprecated cryptographic algorithms, and demonstrated 15 attack types (10 novel) with PASSKEYS-ATTACKER tool. Testing revealed 53 of 103 sites vulnerable to high-severity attacks including account takeover, phishing, and session fixation.

CertSight is an eBPF-based real-time certificate observability tool for Linux that monitors TLS certificate activity across the infrastructure without accessing private keys or requiring application changes. It supports cloud-native, bare metal, and Kubernetes environments, detects certificates via system file access and network events, includes Java support, and provides detailed observability including TLS versions and cipher suites.

ShaderGhost demonstrates a covert tracking mechanism that exploits GPU shader caches to create persistent tracking identifiers that survive standard privacy actions like clearing cookies or restarting browsers. The tracking ID is stored locally on the device through WebGL shader compilation timing side-channels and persists across sites, evading typical browser privacy controls. The article advocates for browsers to partition or clear GPU caches similar to cookie handling.

RFC 10031 defines a new GeneralName form for X.509 certificates to carry IEEE MAC addresses (EUI-48 and EUI-64) in SAN and IAN extensions. It specifies encoding as big-endian octet strings, provides mechanisms for Name Constraints, and enables Layer 2 certificate-based authentication for IoT and automotive networks.

Aegon is a key transparency system for encrypted messaging that enables lightweight end-user auditability at global scale. It uses sharded dictionary design and polynomial commitments to achieve constant-size auditor proofs (under 30 KB) with fast verification (under 65 ms), while maintaining strong privacy and short epoch latency. Prototype results show ~1,250 updates/sec throughput and 80,000× smaller proofs compared to existing approaches like WhatsApp's AKD.

A critique of Simon's claimed quantum algorithm for the Dihedral Coset Problem (DCP), proving that algorithms discarding too much information about Fourier-label coordinates cannot solve DCP in polynomial time. The authors establish a general no-go result and suggest successful DCP solutions require better utilization of Fourier label information.

Google Chrome's policy for establishing a quantum-resistant trust model for TLS using a separate Chrome Quantum-resistant Root Store (CQRS). Rather than adding post-quantum X.509 certificates to the standard root store, Chrome will use Merkle Tree Certificates (MTCs) issued by MTC CA Operators and cosigned by Independent Mirroring Operators for transparency. The policy outlines eligibility requirements, minimum standards for operators, and Google's discretionary authority over participation.

The post critiques IETF standardization procedures for a hybrid ECC+ML-KEM specification in TLS, arguing that working group chairs declared rough consensus to advance the specification despite lacking majority support among participants and unaddressed key objections. The author documents concerns about procedural integrity and governance transparency in IETF decision-making.

Signal introduces Automatic Key Verification, a feature that provides streamlined end-to-end encryption verification through a layered system of user checks, Signal connections, and third-party auditors. It uses key transparency and ledger-based processes to ensure public key consistency without requiring in-person meetings or secondary communication channels.

Google Cloud announces a comprehensive post-quantum cryptography roadmap targeting full PQC readiness by 2029. Key 2026 milestones include deploying quantum-safe key exchange (NIST ML-KEM in hybrid mode) for API endpoints and load balancers supporting hybrid TLS 1.3, offering NIST-standard PQC algorithms (ML-KEM, ML-DSA, SLH-DSA) in Cloud KMS, and collaborating with IETF on PQC PKI standards. The strategy addresses store-now-decrypt-later threats, integrity protection, and covers both internal infrastructure and customer-facing services, with refinements expected through the 2030s as standards evolve.

Trail of Bits explains Signal's Automatic Key Verification (AKV), a key transparency system that prevents server compromise from enabling eavesdropping. AKV uses external auditors (Signal, Cloudflare, and Trail of Bits) to maintain a consistent Merkle-tree-based map of user public keys. The Signal client validates auditor endorsements within seven days; if validation fails, it warns users and they can fall back to manual safety-number verification.