AES-256-GCM

Hybrid Post-Quantum Message Sealing: X25519 + ML-KEM-1024 in Umbera Messenger with Public Rust Tests

Umbera messenger has open-sourced its cryptographic core and published seven Rust tests that anyone can run to verify its hybrid post-quantum message sealing scheme. The design combines X25519 with ML-KEM-1024 so that an attacker must break both algorithms to decrypt a message. Messages are protected by Double Ratchet for forward secrecy, sealed sender packaging, and per-message ephemeral keys derived via HKDF-SHA256 into AES-256-GCM. The relay server stores only an opaque box identifier and encrypted blob with no sender or recipient fields visible. Media calls use DTLS-SRTP end-to-end while TURN servers see only encrypted datagrams. Addresses for message boxes rotate weekly and are derived solely from the shared secret between the two parties.

ProxyKey MCP: Securing API Access for AI Agents Without Exposing Credentials

ProxyKey has released an MCP server that allows AI coding agents such as Claude Code and Cursor to manage API credentials without ever reading the actual secret values. The solution addresses the risk that any key visible to an agent becomes compromised through logging, tracing, or prompt injection. Real provider keys are stored encrypted with AES-256-GCM and never returned by any API endpoint after initial entry. Agents instead receive limited virtual passes that support IP binding, rate limits, TTL, and detailed request logging. A pending-secret workflow lets agents prepare services before the real token exists, with the human entering the secret only through a web panel. The approach deliberately restricts the MCP tool contract so no operation can read or return secret values.

HollowGraph Malware Abuses Microsoft 365 Calendars to Conceal Stolen Files and C2 Traffic

A newly discovered espionage malware called HollowGraph turns compromised Microsoft 365 calendars into hidden channels for receiving commands and exfiltrating stolen data. The implant schedules events for 13 May 2050, a distant future date chosen to reduce the likelihood of discovery by account owners. Developed as a Windows DLL, HollowGraph leverages the Microsoft Graph API to blend its traffic with legitimate corporate service activity, eliminating the need to contact attacker-controlled servers directly. It supports two primary commands: “get” to retrieve instructions attached to operator-created appointments and “send” to encrypt collected data with RSA and AES-256-GCM before uploading it as calendar attachments. Separate encryption keys are used for inbound commands and outbound data, while stolen files are written to a disguised logAzure.txt file. Researchers have identified at least 12 compromised systems, three of which remained active, with operations observed between 3 June and 9 July 2026 and primarily targeting Israeli entities.