cloudflareJul 27, 2026

We’re open sourcing our privacy proxy CLI (opens in new tab)

Oblivious HTTP (OHTTP) is difficult to debug because requests pass through multiple parties, use binary HTTP encoding, and depend on several RFC-defined cryptographic steps. Cloudflare created and open-sourced `pvcli`, a CLI that simplifies testing and troubleshooting privacy protocols by exposing each stage of the process. Released under Apache-2.0, the tool is designed for production-scale debugging and community contributions. ## Why OHTTP Debugging Is Complex - OHTTP ensures that no single party can know both the client’s identity and the requested content. - It relies on two non-colluding servers: - A **relay** that sees the client but not the request contents. - A **gateway** that decrypts the request but does not see the client’s identity. - A typical request proceeds through several stages: - The client retrieves the gateway’s public key. - The client encrypts the request and sends it to the relay. - The relay forwards the anonymized request to the gateway. - The gateway decrypts it and contacts the target. - The response travels back through the gateway and relay before being decrypted by the client. - Every stage can introduce failures, making it difficult to identify whether the problem lies with the client, relay, gateway, or target. ## Why Cloudflare Built `pvcli` - Privacy products such as Privacy Proxy and Privacy Gateway introduced increasing operational complexity and customer-specific requirements. - Engineers frequently had to create one-off clients to test customer deployments. - Diagnosing failures required determining which protocol step had failed and which party was responsible. - OHTTP’s binary formats made manual inspection especially error-prone. - `pvcli` consolidates privacy-protocol functionality into one familiar CLI with support for different protocols and architectures. ## Debugging OHTTP Manually - Engineers first fetch the gateway’s public key, receiving a long hexadecimal binary payload. - They must manually parse fields according to RFC 9458, including: - The key entry length. - The public key identifier. - The asymmetric encryption method, such as DHKEM with X25519 and HKDF-SHA256. - The gateway’s public key. - Supported symmetric encryption algorithms, such as HKDF-SHA256 and AES-128-GCM. - The original HTTP request must then be converted into binary HTTP according to RFC 9292. - Engineers manually verify encoded fields such as: - The request method (`POST`). - The HTTPS scheme. - The target hostname. - The request path and headers. - The JSON body. - Finally, they need custom scripts to encrypt the binary request and construct the OHTTP wrapper request. ## Using `pvcli` - A complete OHTTP request can be issued with a single command: ```bash pvcli --ohttp \ --first-hop https://relay-cloudflare.ohttp.info \ --proxy https://gateway.ohttp.info \ -X POST \ --header "content-type: application/json" \ --data '{"test":1}' \ https://target.ohttp.info/anything ``` - The tool handles the relay, gateway, encryption, binary HTTP encoding, and target request flow. - It provides a clearer view of each protocol step, replacing manual hexadecimal parsing and bespoke scripts with a repeatable debugging workflow. `pvcli` is a practical way to test live OHTTP deployments, isolate failures across the relay and gateway chain, and reduce the risk of mistakes when inspecting binary protocol data.

cryptographyclioblivious-httpbinary-http+3

cloudflareJun 23, 2026

The post-quantum EO is an important milestone. Now it’s time to get to work (opens in new tab)

The post welcomes Executive Order 14409 as a major step toward post-quantum security, setting federal deadlines of 2030 for encryption and 2031 for authentication. It argues that the threat timeline has accelerated and that organizations must begin migration now, especially to prevent “harvest-now-decrypt-later” attacks. Cloudflare views the order as a strong foundation but believes agencies need clearer guidance and a coordinated migration roadmap. ## Federal Post-Quantum Requirements - The order primarily covers: - **High Value Assets (HVAs)**, such as systems containing sensitive employee records, classified intelligence, or federal financial data. - **High impact systems** rated “high” under FIPS 199, where compromise could cause severe harm. - Key deadlines include: - **July 2026:** Agencies name a post-quantum migration lead. - **September 2026:** Agencies inventory HVAs and high-impact systems, create migration plans, and submit them to OMB and the National Cyber Director. - **December 2030:** Key establishment must use post-quantum cryptography. - **December 2031:** Digital signatures and certificates must use post-quantum cryptography. - National Security Systems are excluded from these deadlines and remain on a separate NSA-managed schedule. - The order directly binds federal agencies, not state and local governments, critical infrastructure, academia, or civil society. ## Encryption and Authentication Are Separate Migrations - **Post-quantum encryption** protects key establishment and should begin immediately. - It prevents attackers from collecting encrypted data now and decrypting it after quantum computers become capable of breaking RSA and elliptic-curve cryptography. - This is especially important for government, financial, healthcare, defense, and telecommunications data with long-term value. - **Post-quantum authentication** protects digital signatures, certificates, software signatures, and system access. - It prevents future quantum computers from impersonating servers or forging trusted signatures. - Its primary threat emerges once a cryptographically relevant quantum computer exists. - The order’s 2031 authentication deadline suggests the U.S. government considers an operational quantum computer around that period a meaningful possibility. ## Standardized Cryptography Over Quantum Key Distribution - The order emphasizes NIST-standardized post-quantum algorithms. - The authors support this focus because Quantum Key Distribution requires specialized hardware and dedicated physical links, making it unsuitable for Internet-scale deployment. - Cloudflare reports that more than two-thirds of browser traffic reaching its network already uses post-quantum encryption. - Its Cloudflare One platform supports post-quantum protection across TLS, MASQUE, and IPsec, while broader post-quantum authentication deployment is still beginning. ## Why Authentication Is More Difficult - Post-quantum ML-DSA signatures are larger than traditional signatures, potentially reducing performance in systems such as short-lived TLS connections. - Cloudflare is working with Google Chrome on Merkle Tree Certificates to reduce this TLS overhead. - Authentication requires coordinated upgrades across a larger ecosystem: - Clients and servers - Certificate authorities - Certificate transparency logs - Root stores - Web browsers - By comparison, post-quantum key establishment is already more widely available and easier to deploy incrementally. Organizations should begin with asset inventories, risk assessments, and post-quantum key-establishment upgrades now rather than waiting for the federal deadlines. Authentication migration should also start early because its broader dependency chain and larger signatures make it the more complex transition.

cryptographypost-quantum-cryptographyquantum-computingelliptic-curve-cryptography+3

discordMar 27, 2026

How Multi-Factor Authentication Helps Keep Your Discord Account Safe (opens in new tab)

Discord recommends strengthening accounts with multi-factor authentication (MFA), especially passkeys or authenticator apps. MFA adds protection beyond a password, which can be stolen, guessed, or leaked. The post explains Discord’s available login protections and emphasizes using unique passwords and securely storing recovery credentials. ## Login Verification Emails - Accounts with verified email addresses receive a verification email when signing in from a new device or location. - Users must select “Verify Login” before Discord allows access. - This protection is ineffective if the email account is compromised, particularly when the same password is reused. - Discord strongly recommends using a different password for every online account. ## How Multi-Factor Authentication Works - MFA adds one or more authentication factors beyond a password: - **Something you know:** A password or secret phrase. - **Something you have:** A phone, computer, security key, or other device. - **Something you are:** A fingerprint or facial biometric. - Using multiple factors makes account takeover more difficult. - Enabling any MFA option disables login verification emails. ## Passkeys - Passkeys are presented as Discord’s fastest and most secure option because they are practically phishing-resistant. - They use a cryptographic exchange between Discord and a device, unlocked with a fingerprint, face scan, or device PIN. - Biometric data stays on the user’s device; Discord receives only the cryptographic credential needed to approve the login. - Discord supports up to 16 passkeys per account, including passkeys stored in password managers, browsers, mobile devices, or hardware security keys. - Users are encouraged to keep a backup passkey in a credential manager such as 1Password or Bitwarden. ## Authenticator Apps - Authenticator apps generate time-based one-time passwords. - Discord and the app share a secret starter value, allowing them to generate matching codes. - A new code is created every 30 seconds, while Discord also accepts the previous code to provide roughly a one-minute login window. - Supported apps include Authy, Microsoft Authenticator, and Google Authenticator. - Backup codes should be saved in a password manager or another secure, reliable location. - Backup codes can be regenerated through **My Account > View Backup Codes > Generate New Backup Codes**. ## Recommended Account Protection - Enable MFA on every Discord account. - Prefer one or more passkeys. - Use an authenticator app if passkeys are unavailable. - Use unique passwords across all services. - Store passkeys and backup codes securely, with a backup recovery method available. Overall, Discord recommends passkeys as the strongest option, with authenticator apps as the next-best choice. Login verification emails provide basic protection, but MFA offers substantially stronger defense against stolen or reused passwords.

cryptographymulti-factor-authenticationpasskeysbiometrics+4

cloudflareFeb 27, 2026

Bringing more transparency to post-quantum usage, encrypted messaging, and routing security (opens in new tab)

Cloudflare Radar is expanding its security coverage with new visibility into post-quantum encryption, Key Transparency for encrypted messaging, and ASPA deployment for routing security. The updates extend monitoring from user-to-Cloudflare connections to origin servers, provide tools for testing individual websites, and expose verification data that users can independently inspect. Together, they aim to make emerging Internet security technologies more measurable and transparent. ## Measuring Origin Post-Quantum Support - Cloudflare has tracked browser and client support for post-quantum encryption since 2024, rising from below 3% to more than 60% by February 2026. - The monitored algorithm, `X25519MLKEM768`, combines: - Classical X25519 key exchange - NIST-standardized ML-KEM post-quantum cryptography - Radar now measures whether customer origin servers support the same hybrid key exchange. - Cloudflare’s automated TLS scanner probes TLS 1.3-compatible origins and aggregates results daily. - The data measures algorithm support, not necessarily algorithm preference; a server’s TLS configuration can still choose a classical exchange even when post-quantum support exists. - Approximately 10% of origins currently support post-quantum-preferred key agreement, up from less than 1% in early 2025. - Adoption has accelerated as newer versions of OpenSSL, GnuTLS, and Go enabled hybrid post-quantum support by default. - Origin readiness data is available through Radar, Data Explorer, and the Radar API. ## Website Post-Quantum Compatibility Testing - Radar now includes a tool for testing whether a publicly accessible hostname supports post-quantum encryption. - Users can enter a hostname and optionally specify a port, with HTTPS port 443 used by default. - Results show: - Whether the connection is post-quantum secure - The negotiated TLS key exchange algorithm - The tool uses Cloudflare Containers to run a Go-based TLS scanner. - Because Workers cannot inspect the underlying TLS handshake, the container uses Go’s `crypto/tls` package to perform the connection and report the negotiated algorithm. - Cloudflare has consolidated its client- and origin-facing post-quantum measurements into a dedicated Radar section. ## Key Transparency for Encrypted Messaging - End-to-end encrypted services such as WhatsApp and Signal depend on correct public-key distribution. - If a messaging provider’s key database were compromised, an attacker could replace a contact’s public key and potentially intercept messages without detection. - Key Transparency mitigates this risk through an auditable, append-only public-key log. - The model is comparable to Certificate Transparency: - Messaging services publish users’ public keys to a transparency log. - Independent auditors verify that the log is correctly built and remains consistent. - Radar now provides a public dashboard for Key Transparency Logs used by E2EE messaging services. - The dashboard shows when each log was last signed and verified by Cloudflare’s Auditor. - Users can also access an API to independently validate the Auditor’s proofs. ## Routing Security and ASPA - Radar’s routing security coverage now includes global, country-level, and network-level information about ASPA deployment. - ASPA is an emerging standard intended to help detect and prevent BGP route leaks. - The new data extends Radar’s broader monitoring of Internet routing security. Cloudflare’s additions make post-quantum readiness, encrypted-message key integrity, and routing protection easier to measure and verify. Organizations can use the Radar dashboards, API, and hostname testing tool to assess their own migration and security posture.

cryptographynetwork-securitypost-quantum-cryptographyend-to-end-encryption+4

metaNov 20, 2025

Key Transparency Comes to Messenger (opens in new tab)

Messenger has enhanced the security of its end-to-end encrypted chats by launching key transparency, a system that provides an automated, verifiable record of public encryption keys. By moving beyond manual key comparisons, this feature ensures that users can verify their contacts' identities without technical friction, even when those contacts use multiple devices. This implementation allows Messenger to provide a higher level of assurance that no third party, including Meta, has tampered with or swapped the keys used to secure a conversation. ## The Role of Key Transparency in Encrypted Messaging * Provides a verifiable and auditable record of public keys, ensuring that messages are always encrypted with the correct keys for the intended recipient. * Prevents "man-in-the-middle" attacks by a compromised server by making any unauthorized key changes visible to the system. * Simplifies the user experience by automating the verification process, which previously required users to manually compare long strings of characters across every device their contact owned. ## Architecture and Third-Party Auditing * Built upon the open-source Auditable Key Directory (AKD) library, which was previously used to implement similar security properties for WhatsApp. * Partners with Cloudflare to act as a third-party auditor, maintaining a public Key Transparency Dashboard that allows anyone to verify the integrity of the directory. * Leverages an "epoch" system where the directory is updated and published frequently to ensure that the global log of keys remains current and immutable. ## Scaling for Global Messenger Traffic * Manages a massive database that has already grown to billions of entries, reflecting the high volume of users and the fact that Messenger indexes keys for every individual device a user logs into. * Operates at a high frequency, publishing a new epoch approximately every two minutes, with each update containing hundreds of thousands of new key entries. * Optimized the algorithmic efficiency of the AKD library to ensure that cryptographic proof sizes remain small and manageable, even as the number of updates for a single key grows over time. ## Infrastructure Resilience and Recovery * Improved the system's ability to handle temporary outages and long delays in key sequencing, drawing on two years of operational data from the WhatsApp implementation. * Replaced older proof methods that grew linearly with the height of the transparency tree with more efficient operations to maintain high availability and real-time verification speeds. * Established a robust recovery process to ensure that the transparency log remains consistent even after infrastructure disruptions. By automating the verification of encryption keys through a transparent, audited directory, Messenger has made sophisticated cryptographic security accessible to billions of users. This rollout represents a significant shift in how trust is managed in digital communications, replacing manual user checks with a seamless, background-level guarantee of privacy.

cryptographycloudflaresecurityend-to-end-encryption+2