标签：#cryptography

The Trusted Computing Group has established a new set of requirements to help organizations determine if Trusted Platform Modules are prepared for the era of post-quantum cryptography. This guidance provides a technical benchmark for evaluating whether hardware vendors can protect electronic devices against the future threat of quantum-enabled cyber attacks. Establishing the Post-Quantum Baseline The newly released guidance provides a framework for businesses to verify the security claims made by hardware manufacturers. By creating a standardized set of requirements, the organization ensures that companies can demand proof of protection. This prevents a situation where vendors might claim their products are compliant without offering the full suite of necessary security features. A primary focus of this initiative is the PC Client Platform TPM Profile 1.07. This profile serves as the minimum technical requirement for any module to be considered ready for the next generation of cryptographic challenges. It builds upon the existing TPM 2.0 Library Specification Version 1.85 to include specific elements for quantum-safe protection. Organizations must understand that security in the quantum age involves more than just swapping out one mathematical algorithm for another. True resilience requires a comprehensive approach to hardware-anchored trust. This includes maintaining the integrity of platform identities and attestation over very long periods. Data and identities established today may need to remain secure for several decades. If the underlying hardware is not built to withstand quantum decryption methods, that long-term security is at risk. Current statistics indicate that a vast majority of businesses still lack a formal roadmap for this transition. The Trusted Computing Group president, Joe Pennisi, emphasizes that businesses must look at the broader picture of security. Individual algorithm support is only one piece of the puzzle. Real security comes from a hard

Proteger datos que deben seguir siendo secretos dentro de diez años es un problema de hoy : un adversario puede capturar tu tráfico cifrado ahora y descifrarlo cuando exista la capacidad cuántica ( harvest now, decrypt later ). Quipu es una librería libre de cifrado híbrido post-cuántico para datos en reposo: combina criptografía clásica probada con la nueva, de modo que solo se rompe si ambas caen a la vez. Rust puro, y por qué Quipu nació apuntando a varios lenguajes: un núcleo en Rust con una C ABI encima y bindings para Python, Node y Go. Funcionaba, pero la lección fue clara: mantener una interfaz de C estable más cuatro bindings, cada uno con su empaquetado y sus pruebas de interoperabilidad, era complejidad que no pagaba para el objetivo real —proteger datos en reposo— y ampliaba la superficie de ataque con unsafe que no queríamos. Hoy Quipu es Rust puro : memoria segura, sin garbage collector , sin unsafe de primera parte . Y para quien no programa en Rust, se distribuye como rueda nativa de Python (vía PyO3) — que es la superficie que el cliente que no es de Rust de verdad necesita. Una sola base de código, una sola cosa que auditar. Es la misma filosofía que guía el resto: donde hay buena criptografía, se reutiliza; la simplicidad es una decisión de seguridad, no una comodidad. Instalación cargo add quipu # Rust pip install quipu-crypto # Python (rueda nativa, PyO3) Cifrar y descifrar en Python import quipu # Simétrico con contraseña blob = quipu . encrypt_stream ( b " datos sensibles " , " mi-passphrase " ) assert quipu . decrypt_stream ( blob , " mi-passphrase " ) == b " datos sensibles " # Post-cuántico para un destinatario pub , sec = quipu . generate_keypair () # X25519 + ML-KEM-1024 c = quipu . encode_to_recipient ( b " secreto " , pub ) assert quipu . decode_as_recipient ( c , sec ) == b " secreto " Qué hay debajo Cifrado: XChaCha20-Poly1305 (AEAD autenticado). Derivación de claves: Argon2id (resistente a fuerza bruta) + HKDF. Post-cuántico: X25519

Cryptographic Context Injection is only the latest way to break an LLM safety guardrail.

Modern encryption is almost always AEAD: authenticated encryption with associated data. AES-GCM and ChaCha20-Poly1305 are the two you meet everywhere, in TLS, in disk encryption, in message formats, in cloud key management. They give you confidentiality plus an authentication tag, and decryption either returns the plaintext or returns an error. The security definition behind that tag is about forgery. An attacker who does not know the key cannot produce a ciphertext that verifies. That definition holds. What it says nothing about is the situation where the attacker does know one or more keys and gets to choose the ciphertext. What a key multi-collision looks like Take AES-GCM. Its authentication tag is computed with GHASH, a polynomial evaluation over a binary field, and the relationship between the ciphertext blocks and the tag is linear in that field. Linearity is convenient for speed, and it is also solvable. Given two keys the attacker controls, K1 and K2, that linearity lets them set up a system of equations and solve for a ciphertext whose tag verifies under both. Decrypting it with K1 yields one plaintext. Decrypting the same bytes with K2 yields a completely different plaintext. Neither decryption throws an error, because from each key's point of view the tag is correct. Both plaintexts can be attacker-chosen and meaningful. The 2019 paper that named this attack demonstrated a file that was a valid image either way, which is where the memorable label came from: the two decryptions showed different pictures, and the second one had a salamander in it that the reporting system never saw. The property that was missing. An AEAD is key committing if a ciphertext can verify under at most one key. AES-GCM, AES-GCM-SIV, and ChaCha20-Poly1305 are not key committing, and were never claimed to be. The property simply was not part of the design goal, and for a long time no widely deployed system depended on it. The system it broke: message franking Here is the problem th

This is good : Post-quantum cryptography is now one pip-install away for the entire Python ecosystem. With funding from the Sovereign Tech Agency , we implemented support for ML-KEM, the NIST-standard key-establishment primitive, and ML-DSA, the NIST-standard digital-signature primitive, in pyca/cryptography. Remember, the reason to do this now is because there’s no emergency. And because you will make your systems crypto agile, which is always a good idea.

A tutorial where you prove things without revealing things, and yes, the math actually maths. Here's something the internet doesn't want you to know: you overshare every single time you prove something. Prove you're over 21 at a bar? You hand over a card with your name, your address, your height, and your terrible 2019 haircut. Prove your income to a landlord? Here's every transaction I've made since college, please don't judge the 3am food delivery. We built the entire digital world on a verification model that boils down to "here's everything, trust me bro." Not anymore. There's a branch of cryptography that lets you prove a statement is true while revealing nothing else . It sounds fake. It's called a zero knowledge proof , and by the end of this article you'll understand one well enough to check it with Python. Then we'll look at Midnight , a blockchain that turned this party trick into a developer platform. Let's go. 🚀 🪪 The Trust Me Bro Problem Every verification system you use today works by disclosure . You prove things by showing the underlying data: Prove your age ➡️ show your whole ID Prove you can pay ➡️ show your bank statements Prove you're a real user ➡️ solve a CAPTCHA and sacrifice your data to the algorithm gods The data doesn't just get seen . It gets stored , and eventually it gets breached , and then a guy named xX_darkweb_Xx is selling your identity for the price of a burrito. The verifier never needed the data. They needed one bit of information : true or false. Everything else was collateral damage. In short: we've been answering yes or no questions with our entire life story. 🕵️ The Party Trick That Started It All Zero knowledge proofs let a prover convince a verifier that a statement is true without revealing why it's true. The classic example is Where's Waldo. Say I claim I found Waldo on the page and you don't believe me (fair, you've seen my code reviews). I could point at him, but then I've revealed the answer and ruined the puzzle. Ins

Passwords are broken. They get leaked in database breaches, reused across platforms, and phished through clever domain spoofs. While Multi-Factor Authentication (MFA) helps, standard SMS or OTP codes still leave major security gaps. Enter Passkeys : a modern authentication standard built on top of WebAuthn and FIDO2 specifications designed to eliminate shared secrets entirely. Here is a dive into the underlying cryptography, architectural flow, and why passkeys are inherently phishing-proof. The Core Concept: Asymmetric Cryptography Traditional authentication relies on shared secrets . Both you and the server know your password (or a hashed version of it). To verify who you are, you send that secret over the network. Passkeys replace shared secrets with asymmetric (public/private key) cryptography : Private Key: Generated locally on your device and stored inside a Hardware Security Module (like Apple's Secure Enclave, Android's Titan chip, or a YubiKey) or an end-to-end encrypted sync service (iCloud Keychain, 1Password, Google Password Manager). It never leaves your device unencrypted. Public Key: Registered with and stored by the website (the Relying Party). It is completely public and mathematically useless to an attacker on its own. Architectural Breakdown: How It Works Passkey operations consist of two cryptographic phases: Registration and Authentication . Phase 1: Registration (Generating the Keypair) When you create a passkey for a service (e.g., app.example.com ): Challenge Request: Your client initiates registration. The server generates a cryptographic challenge (a high-entropy random string) and sends it back alongside origin metadata ( RP ID ). Local Verification: Your browser hands this request to the OS/authenticator, which prompts for user verification—biometrics (Face ID/Touch ID/Windows Hello) or a hardware PIN. KeyPair Generation: Once unlocked, the hardware generates a unique keypair bound exclusively to app.example.com . Public Key Registration:

Every signal in the previous articles is statistical. They weigh evidence, they have thresholds, they can be argued with. Honeytokens are different in kind. A honeytoken is a record that does not exist and was never given to anyone . Nothing legitimate can ask for it, because nothing legitimate has ever held a reference to it. A request for one isn't suspicious — it's proof that someone is guessing or working from a stolen list. That makes it the highest-confidence signal available, and worth building carefully. Derivation: make the decoy recognise itself The obvious implementation is a table. Generate decoy IDs, store them, and check every miss against the table. That has two problems. It puts a database lookup in the request path on every miss — and misses are exactly what a flood produces. And it doesn't tell you whose decoy was tripped without another join. Instead, derive them: export function honeytokenFor ( clientId : string , n : number , generation = 0 ): string { const mac = createHmac ( ' sha256 ' , config . honeytokenSecret ) . update ( ` ${ clientId } : ${ generation } : ${ n } ` ) . digest (); return uuidFromBytes ( mac . subarray ( 0 , 16 )); } Three properties fall out of this, and they're the whole design: Recognition is stateless. Given any ID and any client, recompute the client's decoy set and check membership. No lookup, no cache, no round trip. The gateway precomputes each known client's set at startup into a Set and membership is O(1). Attribution is automatic. The client ID is inside the derivation. There is no "which client did this decoy belong to?" question — a decoy for integration-acme is not a decoy for anyone else, and cannot be. If a decoy seeded into acme's scope is requested by a different credential, that's information too. They're format-identical to real IDs. The output is shaped as a v4 UUID — correct version and variant nibbles — so it is indistinguishable from a real documents identifier: export function uuidFromBytes ( bytes

Una discusión sobre un archivo digital casi nunca se pierde por lo que el archivo dice. Se pierde una pregunta antes: ¿Cómo sabemos que ese es el archivo que usted recibió, y no el que editó anoche? Si la respuesta es "confíe en mí", ya perdiste. Y da igual cuánta razón tengas en el fondo. Este problema no es exclusivo de un juzgado. Lo tiene el auditor que recibe un volcado de logs, el equipo que documenta un incidente, quien conserva la copia de un contrato firmado por correo. En todos los casos hace falta lo mismo: poder demostrar que un conjunto de bytes no cambió desde un momento determinado, y que lo demuestre alguien que no seas tú . Para eso escribí Tunjo : una herramienta en Rust que recorre un material en solo lectura, calcula su huella y firma un acta verificable por cualquiera. Por qué un árbol y no un hash Lo obvio sería concatenar todo y sacar un SHA-256. Funciona, y es inútil en la práctica. Cuando alguien discute un archivo —un correo concreto entre cuatro mil— con un hash único solo puedes ofrecer dos cosas: o entregas el conjunto completo para que se recalcule, o pides que te crean. La primera opción expone material que no tiene por qué exponerse; la segunda no es una prueba. Un árbol de Merkle resuelve exactamente eso. Cada archivo es una hoja, cada par de nodos se combina hacia arriba y queda una raíz. Para demostrar que una hoja pertenece a esa raíz basta con exhibir esa hoja y el camino de hashes hasta arriba: unos pocos kilobytes. El resto del conjunto no se toca. Dos detalles del árbol que no son opcionales: // Separación de dominio: una hoja nunca puede hacerse pasar por nodo interno. h . update ([ 0x00 ]); // hoja h . update ([ 0x01 ]); // nodo interno // Y la raíz ata el número de hojas. h . update ([ 0x02 ]); h . update ( n . to_be_bytes ()); Sin lo primero, un hash de hoja podría presentarse como si fuera un nodo del árbol. Sin lo segundo aparece la ambigüedad clásica de los árboles con número impar de hojas: dos conjuntos distintos pued

Encrypted data stored in cloud archives today will outlive the mathematical algorithms guarding it. In enterprise architectures that handle long-term records, like construction risk logs or employee compliance platforms, data retention schedules often span twenty to thirty years. When building cloud pipelines that move this information across services, we depend heavily on asymmetric encryption, which is a security method using one public key to lock data and a separate private key to unlock it. Standard public-key algorithms rely on mathematical problems that are nearly impossible for classical computers to solve within a reasonable human timeframe. Quantum computing changes this equation entirely. Quantum computers leverage quantum mechanics, the physical rules governing subatomic particles, to perform calculations at speeds fundamentally unimaginable with traditional silicon processors. While powerful quantum systems are still in development, the security threat to distributed systems exists today. Hostile actors do not need to crack modern security algorithms in real time. Through a pattern known as Harvest Now, Decrypt Later, adversaries can capture and store encrypted network traffic right now. They simply wait until future quantum hardware becomes capable of running the formulas required to decrypt that stolen history. For software architects, preparing for post-quantum cryptography, which refers to new mathematical encryption algorithms designed to withstand quantum attacks, is far more than a simple library swap. It is a deep distributed systems migration challenge. The primary operational hurdle is payload size and computational overhead. Quantum-resistant algorithms require significantly larger digital keys and payload headers than the standards we rely on today. When cryptographic payloads expand, every component of a distributed platform feels the ripple effect. Message queues experience higher bandwidth demands. Database indexes inflate. Memory consump

In October 2017, researcher Mathy Vanhoef published an attack that broke WPA2, the encryption that had protected almost every Wi-Fi network on the planet for over a decade. The surprise was how it worked. KRACK did not guess your Wi-Fi password or brute-force any key. It tricked your device into installing a key it had already used, and that single mistake unraveled the encryption. WPA2 replaced the badly broken WEP standard in 2004 and quickly became the baseline for wireless security. For thirteen years it held up well. The passphrase-based version most homes use (WPA2-Personal) was vulnerable to offline password guessing if you chose a weak passphrase, but the protocol itself was considered sound. KRACK, short for Key Reinstallation Attack, was different. It targeted a flaw in the WPA2 standard itself, which meant every correct implementation was affected. The four-way handshake, briefly When a device joins a WPA2 network, the client and the access point run a four-message exchange called the four-way handshake. Both sides already share a secret (derived from the passphrase or from an enterprise authentication server). The handshake uses that shared secret to agree on a fresh session key, the Pairwise Transient Key, that will actually encrypt the traffic for this session. The important part is message three. The access point sends message three to tell the client the key is ready, and the client responds with message four and installs the key. Once installed, that key encrypts frames using a counter, called a nonce or packet number, that increments with every frame. The security of the encryption depends on one rule: a given key must never encrypt two different frames with the same nonce. The reinstallation trick Wi-Fi is a lossy medium. Messages get dropped. So the standard says that if the access point does not receive message four, it retransmits message three. When the client receives a retransmitted message three, it reinstalls the same key and, critically,

When I set out to build a provably-fair random selection system on Solana, the obvious choice for randomness was a VRF (Verifiable Random Function). Instead, I built the system around Solana's SlotHashes sysvar with a commit-reveal scheme. Here's why, and what I gave up to get there. The problem A fair-selection system needs a winner (or set of winners) chosen in a way that's fair, and just as important that participants can check for themselves without taking anyone's word for it. VRF services (Switchboard, ORAO, etc.) solve the fairness part well: they produce randomness that's unpredictable in advance and cryptographically provable after the fact. But they come with a dependency on an oracle, a fee per request, and a proof that most users will never actually verify they'll trust it because the crypto math says they can, not because they did. I wanted something a participant with no crypto background could check in a browser console. The approach: commit-reveal with slot hashes The core idea: commit to the participant list before you know the randomness, then derive the randomness from a slot hash you couldn't have predicted at commit time. rust fn derive_randomness(target_hash: &[u8; 32], participant_root: &[u8; 32]) -> [u8; 32] { let mut combined_seed = [0u8; 64]; combined_seed[..32].copy_from_slice(target_hash); // slot hash at reveal combined_seed[32..].copy_from_slice(participant_root); // Merkle root, locked at commit solana_keccak_hasher::hash(&combined_seed).to_bytes() } The flow: Commit: participant list is finalized and hashed into a Merkle root; this is written on-chain. Wait: a target slot in the future is chosen as the reveal point. Reveal: once that slot passes, its hash is pulled from SlotHashes and combined with the committed root to derive the randomness. Select: the randomness deterministically picks winners from the participant set; winners get their own Merkle root and proofs. Every draw ends up with an audit record like: rust pub struct AuditR

Really interesting piece of cryptographic history : In November 2023, a large cache of his wartime papers—nicknamed the “Bayley papers”—was auctioned in London for almost half a million U.S. dollars. The previously unknown cache contains many sheets in Turing’s own handwriting, telling of his top-secret “Delilah” engineering project from 1943 to 1945. Delilah was Turing’s portable voice-encryption system, named after the biblical deceiver of men. There is also material written by Bayley, often in the form of notes he took while Turing was speaking. It is thanks to Bayley that the papers survived: He kept them until he died in 2020, 66 years after Turing passed away...

The problem Websites have SSL certificates. Browsers verify them. Users trust them. It's the foundation of the web. AI agents have nothing . When Agent A connects to Agent B: ❌ No way to verify B's identity (anyone can impersonate) ❌ No way to check B's trustworthiness (no audit, no reputation) ❌ No encryption (messages are plaintext) ❌ No standard payment method ❌ No way to translate between frameworks (LangChain ≠ AutoGen) So I built ATC — Agent Trust Card . What is ATC? ATC is like an SSL certificate + passport + credit card for AI agents, all in one: Identity — Cryptographically signed by MarketNow (we're the Certificate Authority) Trust — Contains a Sentinel security audit score (0-10) Encryption — Contains an Ed25519 public key for end-to-end encrypted messaging Translation — Specifies the agent's framework; MarketNow translates between them Payment — Contains a USDC wallet address for autonomous payments How it works Agent A generates Ed25519 keypair ↓ Agent A requests ATC from MarketNow ↓ MarketNow runs Sentinel audit → signs ATC ↓ Agent A presents ATC when connecting to Agent B ↓ Agent B verifies A's ATC signature (using MarketNow's CA public key) ↓ Agent B checks A's trust score (rejects if below threshold) ↓ They communicate — end-to-end encrypted ↓ Agent A pays Agent B — USDC with escrow ↓ Both rate each other — trust scores update The code # Request an ATC POST https://marketnow.site/api/atc { "action" : "issue" , "agent_id" : "agent.yourorg.yourname" , "agent_name" : "Your Agent" , "public_key" : "Ed25519 public key" , "capabilities" : [ "web_scraping" ] , "protocol_language" : "langchain" , "wallet_address" : "0x..." } # Verify an ATC GET https://marketnow.site/api/atc?action = verify&card_id = ATC-2026-00001 # Get CA public key (for signature verification) GET https://marketnow.site/api/atc?action = ca-key What makes ATC different from existing solutions Feature AgentID Agent Passport IBM ACP Stripe ACP ATC Cryptographic identity ✅ ✅ ❌ ❌ ✅ Security a

Everyone who has ever been right about something loud enough to remember it will tell you they called it. The screenshot arrives after the match, after the candle, after the election. And there is no way to know whether it was written on Monday or edited on Friday. This is the quiet rot at the center of most "track records": a prediction you cannot date is not a prediction at all. It is a memory with good lighting. The technical name for the problem is look-ahead . If a forecast can be created, tweaked, or cherry-picked after the outcome is known, then it carries zero information about skill. The only fix is to make the timing of a prediction independently checkable вАФ to prove a document existed in a specific form before a specific moment, without asking anyone to trust you, your server clock, or your database. That is precisely what OpenTimestamps does, using the Bitcoin blockchain as a shared, tamper-evident clock. Why timing is the whole game A forecast is a bet against the future. Its value comes entirely from the fact that the future was unknown when the forecast was fixed. The instant you allow post-hoc editing, every desirable property collapses: calibration becomes meaningless, Brier scores become fiction, and "I predicted this" becomes unfalsifiable. So an honest forecasting system needs one hard guarantee before anything else: this exact text existed at this exact time, and has not changed since. Note what that guarantee does not require. It does not require publishing the forecast publicly in advance (you might want it sealed). It does not require a notary, a lawyer, or a trusted timestamping company that could be subpoenaed, hacked, or simply go out of business. It requires a clock that nobody controls and nobody can wind backward. What "proof of existence" actually means The building block is a cryptographic hash вАФ typically SHA-256. Feed any file into it and you get a 64-character fingerprint. Change a single comma and the fingerprint changes compl

France is accelerating its transition to post-quantum encryption: France’s cybersecurity agency ANSSI said on Tuesday it would stop certifying security products that lack quantum-resistant encryption, a move that will force government bodies and critical operators to shift away from older systems. Samih Souissi, ANSSI’s chief of staff, said at the France Quantum conference that the agency would halt such certifications from 2027, and that businesses should be buying only quantum-safe products by 2030. ANSSI approval is required for use in French government agencies and critical infrastructure, making the policy a de facto phase-out of older encryption...

Your codebase almost certainly relies on RSA and elliptic-curve cryptography — TLS, JWTs, SSH keys, signed tokens. All of it is breakable by a large enough quantum computer (Shor's algorithm), and "harvest now, decrypt later" means data you encrypt today can be captured today and decrypted later. Regulators noticed: CNSA 2.0 (US federal + suppliers), DORA (EU financial entities, applies from Jan 2025), and NIS2 now mandate strict cryptographic risk management — which in practice means knowing where your quantum-vulnerable crypto lives, a cryptographic bill of materials (CBOM). Most teams can't answer "where is our RSA/ECC?" off the top of their head. Here's how to make CI answer it for you, on every push, for free. What we're building A GitHub Action that scans your repo, grades its post-quantum readiness A–F , writes a CycloneDX 1.6 CBOM , and — if you want — fails the build when classically-broken crypto (MD5, RC4, 3DES, deprecated TLS) shows up. Step 1 — try it in your browser first (30 seconds, nothing uploaded) Before touching CI, paste a package.json / requirements.txt / cipher list into the in-browser scanner and see your grade. It runs entirely client-side — no upload: https://throndar.ai/cbom Step 2 — add it to CI (the 5 lines) # .github/workflows/pqc-readiness.yml name : PQC readiness on : [ push , pull_request ] jobs : scan : runs-on : ubuntu-latest steps : - uses : actions/checkout@v4 - uses : brandonjsellam-Releone/pq-readiness-scorecard@v1 with : path : . That's it. The Action is self-contained and dependency-free — no npm install , no setup step. On the next push it prints a scorecard to the job summary: Post-Quantum Readiness Scorecard: D (52/100) — Quantum-vulnerable — migrate 3 files · broken-classical 0 · quantum-broken 4 · weakened 1 · resistant 0 Step 3 — see findings in the Security tab (SARIF) The Action emits SARIF 2.1.0. Upload it and every finding shows up as a code-scanning alert: - id : pqc uses : brandonjsellam-Releone/pq-readiness-score

Every major cloud provider sells a key management service, and most sell a "bring your own key" option layered on top, marketed as the difference between trusting the provider and trusting yourself. The pitch is clean. The mechanics underneath are not, and the part that actually determines who can read your data is rarely the part the sales page shows you. If you've provisioned storage on AWS, Google Cloud, or Azure in the last few years, you've seen the encryption-at-rest checkbox: "encrypt with a key you manage." It sounds like a meaningful control. In practice it's three different architectures wearing the same marketing label, and they don't provide the same guarantee. What a KMS Actually Does A cloud Key Management Service is a hosted service that generates, stores, and performs operations with cryptographic keys on your behalf. When you ask a KMS to encrypt something, in most cases the plaintext key material never leaves the service's boundary. What you get back is a ciphertext blob and, for envelope encryption schemes, a wrapped data key you can use locally. The design goal is real: keys shouldn't sit in application memory or config files where a compromised host can grab them. The question that matters is not "does a KMS exist in this architecture" but "who can invoke it, and under what legal or operational conditions." That's where customer-managed keys and bring-your-own-key start to diverge in ways the naming doesn't make obvious. Customer-Managed Keys vs Bring-Your-Own-Key Customer-managed keys (CMK) means the key was generated inside the provider's KMS, under your account, and you control the access policy: who can use it, when it rotates, whether it can be disabled. The key material itself still lives entirely inside the provider's infrastructure. You never see the raw bytes. You're managing permissions on a key you didn't generate and can't export. Bring-your-own-key (BYOK) means you generate the key material yourself, outside the provider's environme

Interesting research on a new class of weak RSA keys: keys with lots of zeros. It turns out that these keys are out in the wild. The badkeys project is an open-source service that checks public keys for known vulnerabilities. While developing this tool, Hanno collected a massive number of real-world keys from public sources, including Certificate Transparency logs, internet-wide TLS and SSH scans, PGP keys, and many others. By searching this dataset for unexpectedly sparse RSA moduli, we uncovered a large number of keys in the wild with the patterns in Figure 1...

If you ship a desktop app outside an app store, you eventually hit the same wall: how do you check a license when the user is on a plane, behind a corporate firewall, or just offline? Calling your server on every launch isn't an option. Here's how offline activation actually works, without the hand-waving. The naive version, and why it breaks The first thing everyone reaches for is "call home on launch, get back yes/no." It works in the demo and fails in the wild: No network = no app. Fail-closed locks out paying customers. Fail-open means anyone who blocks your domain runs free. Both are bad. A boolean is forgeable. If your app trusts a {"valid": true} response, a proxy or a patched DNS entry returns that for free. The fix isn't a better endpoint. It's moving the trust off the network and onto cryptography. The model that works: signed leases The durable pattern is a cryptographically signed lease (Keygen calls these license files, Keylight calls them leases — same idea): On first activation, the device talks to the server once . The server returns a small signed document: the license state, an expiry, the device binding, and any entitlements (which features/tiers are unlocked). The document is signed with the server's private key (Ed25519 is the modern choice — small, fast, boring in the good way). Your app ships the matching public key and verifies the signature locally on every launch. No network needed. Because the app only ever verifies with a public key, there's nothing secret in the binary to steal, and a forged lease fails the signature check. That's the whole trick: the server vouches once, math vouches forever after. first launch ──► server signs lease (Ed25519, private key) ──► stored on device every launch ──► app verifies signature (public key) ──► no network Device binding (so one key isn't infinite installs) A lease is bound to a device so a single license can't be pasted onto a thousand machines. The lease embeds a device fingerprint, and the SDK ch