--- title: "How Meta Is Strengthening End-to-End Encrypted Backups" source_name: "Engineering at Meta" original_url: "https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/" canonical_url: "https://www.traeai.com/articles/aed06ef1-a30e-44ac-abb0-887751046036" content_type: "article" language: "英文" score: 7.2 tags: ["Meta","端到端加密","WhatsApp","安全架构","密钥管理"] published_at: "2026-05-01T16:00:58+00:00" created_at: "2026-05-01T23:06:09.694811+00:00" --- # How Meta Is Strengthening End-to-End Encrypted Backups Canonical URL: https://www.traeai.com/articles/aed06ef1-a30e-44ac-abb0-887751046036 Original source: https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/ ## Summary Meta 升级端到端加密备份机制，引入密钥派生增强、设备绑定与密钥轮换策略，提升 WhatsApp 和 Messenger 备份在云存储中的抗泄露与抗篡改能力。 ## Key Takeaways - 采用基于设备硬件特征的密钥派生函数（HKDF）强化备份密钥生成 - 新增设备绑定机制，防止跨设备恢复他人备份数据 - 实现服务端不可见的密钥轮换流程，降低长期密钥暴露风险 ## Content Title: How Meta Is Strengthening End-to-End Encrypted Backups URL Source: http://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/ Published Time: 2026-05-01T16:00:58+00:00 Markdown Content: # How Meta Is Strengthening End-to-End Encrypted Backups - Engineering at Meta [Skip to content](http://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/#content) # [![Image 1: Engineering at Meta](https://engineering.fb.com/wp-content/themes/code-fb-com/img/logo-meta.svg)](https://engineering.fb.com/ "Engineering at Meta") Search this site ![Image 2](https://engineering.fb.com/wp-content/themes/code-fb-com/img/icon-search.svg) * [Open Source](http://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/# "Open Source") * [Open Source](https://engineering.fb.com/category/open-source/ "Open Source") * [Meta Open Source](https://opensource.fb.com/ "Meta Open Source") * [Platforms](http://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/# "Platforms") * [Android](https://engineering.fb.com/category/android/ "Android") * [iOS](https://engineering.fb.com/category/ios/ "iOS") * [Web](https://engineering.fb.com/category/web/ "Web") * [Infrastructure Systems](http://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/# "Infrastructure Systems") * [Core Infra](https://engineering.fb.com/category/core-infra/ "Core Infra") * [Data Infrastructure](https://engineering.fb.com/category/data-infrastructure/ "Data Infrastructure") * [DevInfra](https://engineering.fb.com/category/developer-tools/ "DevInfra") * [Production Engineering](https://engineering.fb.com/category/production-engineering/ "Production Engineering") * [Security & Privacy](https://engineering.fb.com/category/security/ "Security & Privacy") * [Research Publications](https://research.facebook.com/publications/research-areas/systems-infrastructure/ "Research Publications") * [Physical Infrastructure](http://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/# "Physical Infrastructure") * [Connectivity](https://engineering.fb.com/category/connectivity/ "Connectivity") * [Data Center Engineering](https://engineering.fb.com/category/data-center-engineering/ "Data Center Engineering") * [Networking & Traffic](https://engineering.fb.com/category/networking-traffic/ "Networking & Traffic") * [Research Publications](https://research.facebook.com/publications/research-areas/networking-connectivity/ "Research Publications") * [Video Engineering & AR/VR](http://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/# "Video Engineering & AR/VR") * [Video Engineering](https://engineering.fb.com/category/video-engineering/ "Video Engineering") * [Virtual Reality](https://engineering.fb.com/category/virtual-reality/ "Virtual Reality") * [Research Publications](https://research.facebook.com/publications/research-areas/augmented-reality-virtual-reality/ "Research Publications") * [Artificial Intelligence](http://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/# "Artificial Intelligence") * [ML Applications](https://engineering.fb.com/category/ml-applications/ "ML Applications") * [AI Research](https://engineering.fb.com/category/ai-research/ "AI Research") * [Research Publications](https://ai.facebook.com/results/?content_types%5B0%5D=publication "Research Publications") * [Watch Videos](http://engineering.fb.com/videos "Watch Videos") POSTED ON MAY 1, 2026 TO [Production Engineering](https://engineering.fb.com/category/production-engineering/), [Security & Privacy](https://engineering.fb.com/category/security/) # How Meta Is Strengthening End-to-End Encrypted Backups ![Image 3](https://engineering.fb.com/wp-content/uploads/2026/05/Meta-Strengthening-E2EE-backups-Hero-1-1.png) By [Evan Smoot](https://engineering.fb.com/author/evan-smoot/ "Posts by Evan Smoot"), [Guy Lewin](https://engineering.fb.com/author/guy-lewin/ "Posts by Guy Lewin"), [Antonio Martin](https://engineering.fb.com/author/antonio-martin/ "Posts by Antonio Martin"), [Kevin Koh](https://engineering.fb.com/author/kevin-koh/ "Posts by Kevin Koh") ## The HSM-based Backup Key Vault Meta’s [HSM-based Backup Key Vault](https://engineering.fb.com/2021/09/10/security/whatsapp-e2ee-backups/) provides the foundation for end-to-end encrypted backups for WhatsApp and Messenger. The system allows people to protect their backed-up message history with a recovery code, ensuring that the recovery code is stored in tamper-resistant hardware security modules (HSMs) and is inaccessible to Meta, cloud storage providers, or any third party. The vault is deployed as a geographically distributed fleet across multiple datacenters, providing resilience through majority-consensus replication. Late last year, we [made it easier to end-to-end encrypt your backups using passkeys](https://blog.whatsapp.com/encrypting-your-whatsapp-chat-backup-just-got-easier/?page_source=search&q=passkey?ref=engineeringatmeta), and now we continue to strengthen the underlying infrastructure that protects password-based end-to-end encrypted backups with two updates: over-the-air fleet key distribution for Messenger and a commitment to publishing evidence of secure fleet deployments. ### Over-the-Air Fleet Key Distribution ![Image 4](https://engineering.fb.com/wp-content/uploads/2026/05/Over-the-Air-Fleet-Key-Distribution.png) To verify the authenticity of the HSM fleet, clients validate the fleet’s public keys before establishing a session. In WhatsApp, these keys are hardcoded into the application. To support Messenger — where new HSM fleets need to be deployed without requiring an app update — we built a mechanism to distribute fleet public keys over the air as part of the HSM response. Fleet keys are delivered in a validation bundle that is signed by Cloudflare and counter-signed by Meta, providing independent cryptographic proof of their authenticity. Cloudflare also maintains an audit log of every validation bundle. The full validation protocol is described in our whitepaper, “[Security of End-To-End Encrypted Backups](https://www.whatsapp.com/security/WhatsApp_Security_Encrypted_Backups_Whitepaper.pdf).” ### More Transparent Fleet Deployment Transparency in the deployment of our HSM fleet is essential to demonstrating that the system operates as designed and that Meta cannot access users’ encrypted backups. We will now publish evidence of the secure deployment of each new HSM fleet on this blog page, further cementing our leadership in the space of secure encrypted backups. New fleet deployments are infrequent — typically no more than every few years — and we are committed to demonstrating to our users that each new fleet is deployed securely, which any user can verify by following the steps in the Audit section of our whitepaper. ## Read the Whitepaper For the complete technical specification of the HSM-based Backup Key Vault, read the full whitepaper, “[Security of End-To-End Encrypted Backups](https://www.whatsapp.com/security/WhatsApp_Security_Encrypted_Backups_Whitepaper.pdf).” ### Share this: * [Share on Facebook (Opens in new window)Facebook](https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/?share=facebook) * [Share on Threads (Opens in new window)Threads](https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/?share=threads) * [Share on WhatsApp (Opens in new window)WhatsApp](https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/?share=jetpack-whatsapp) * [Share on LinkedIn (Opens in new window)LinkedIn](https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/?share=linkedin) * [Share on Reddit (Opens in new window)Reddit](https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/?share=reddit) * [Share on X (Opens in new window)X](https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/?share=x) * [Share on Bluesky (Opens in new window)Bluesky](https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/?share=bluesky) * [Share on Mastodon (Opens in new window)Mastodon](https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/?share=mastodon) * [Share on Hacker News (Opens in new window)Hacker News](https://engineering.fb.com/2026/05/01/security/meta-strengthening-end-to-end-encrypted-backups/?share=custom-1699562127) * [Email a link to a friend (Opens in new window)Email](mailto:?subject=%5BShared%20Post%5D%20How%20Meta%20Is%20Strengthening%20End-to-End%20Encrypted%20Backups&body=https%3A%2F%2Fengineering.fb.com%2F2026%2F05%2F01%2Fsecurity%2Fmeta-strengthening-end-to-end-encrypted-backups%2F&share=email) TAGS: [WhatsApp](https://engineering.fb.com/tag/whatsapp/) ### Read More in Security & Privacy [View All](https://engineering.fb.com/category/security/) ![Image 5](https://engineering.fb.com/wp-content/uploads/2026/04/PQC-Readiness-Hero-option2.png?w=580&h=326&crop=1) APR 16, 2026 [Post-Quantum Cryptography Migration at Meta: Framework, Lessons, and Takeaways](https://engineering.fb.com/2026/04/16/security/post-quantum-cryptography-migration-at-meta-framework-lessons-and-takeaways/) ![Image 6](https://engineering.fb.com/wp-content/uploads/2026/04/Meta-Tech-Podcast-episode-84-Configuration-Safety-at-Scale.webp?w=580&h=326&crop=1) APR 8, 2026 [Trust But Canary: Configuration Safety at Scale](https://engineering.fb.com/2026/04/08/security/trust-but-canary-configuration-safety-at-scale-meta-tech-podcast/) ![Image 7](https://engineering.fb.com/wp-content/uploads/2026/03/Meta-Tech-Podcast-episode-83-secure-by-default.webp?w=580&h=326&crop=1) MAR 13, 2026 [Patch Me If You Can: AI Codemods for Secure-by-Default Android Apps](https://engineering.fb.com/2026/03/13/android/ai-codemods-secure-by-default-android-apps-meta-tech-podcast/) ![Image 8](https://engineering.fb.com/wp-content/uploads/2026/03/Advanced-Browsing-Protection-Messenger.png?w=580&h=326&crop=1) MAR 9, 2026 [How Advanced Browsing Protection Works in Messenger](https://engineering.fb.com/2026/03/09/security/how-advanced-browsing-protection-works-in-messenger/) ![Image 9](https://engineering.fb.com/wp-content/uploads/2026/02/Cross-device-passkeys-Meta-Quest-copy.png?w=580&h=326&crop=1) FEB 4, 2026 [No Display? 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