---
title: Security
product: vercel
url: /docs/vercel-blob/security
canonical_url: "https://vercel.com/docs/vercel-blob/security"
last_updated: 2026-06-24
type: conceptual
prerequisites:
  - /docs/vercel-blob
related:
  - /docs/vercel-blob/private-storage
  - /docs/functions
  - /docs/vercel-firewall
  - /docs/vercel-firewall/vercel-waf
  - /docs/vercel-firewall/vercel-waf/custom-rules
summary: Learn how your Vercel Blob store is secured
install_vercel_plugin: npx plugins add vercel/vercel-plugin
---

# Security

> **🔒 Permissions Required**: Vercel Blob

## Private storage

For files that require authentication, use [private storage](/docs/vercel-blob/private-storage). Private Blob stores require authentication for all read and write operations. When your code runs on Vercel, the SDK uses OpenID Connect (OIDC) by default. OIDC is preferred over the long-lived `BLOB_READ_WRITE_TOKEN` because its tokens rotate automatically. Use `BLOB_READ_WRITE_TOKEN` when code runs outside Vercel or for client uploads. Files in private Blob stores cannot be accessed via public URLs. You deliver them to your users through [Vercel Functions](/docs/functions) where you implement your own authentication logic.

## Public storage security

Vercel Blob URLs, although publicly accessible, are unique and hard to guess when you use the `addRandomSuffix: true` option. They consist of a unique store id, a pathname, and a unique random blob id generated when the blob is created.

> **💡 Note:** This is similar to [Share a file
> publicly](https://support.google.com/drive/answer/2494822?hl=en\&co=GENIE.Platform%3DDesktop#zippy=%2Cshare-a-file-publicly)
> in Google Docs. You should ensure that the URLs are only shared to authorized
> users

Headers that enhance security by preventing unauthorized downloads, blocking external content from being embedded, and protecting against malicious file type manipulation, are enforced on each blob. They are:

- `content-security-policy`: `default-src "none"`
- `x-frame-options`: `DENY`
- `x-content-type-options`: `nosniff`
- `content-disposition`: `attachment/inline; filename="filename.extension"`

### Encryption

All files stored on Vercel Blob are secured using AES-256 encryption. This encryption process is applied at rest and is transparent, ensuring that files are encrypted before being saved to the disk and decrypted upon retrieval.

### Firewall and WAF integration 

Vercel Blob is protected by Vercel's [platform-wide firewall](/docs/vercel-firewall#platform-wide-firewall) which provides DDoS mitigation and blocks abnormal or suspicious levels of incoming requests.

You can also protect a store with your own [Vercel WAF](/docs/vercel-firewall/vercel-waf) rules, such as [custom rules](/docs/vercel-firewall/vercel-waf/custom-rules), [IP blocking](/docs/vercel-firewall/vercel-waf/ip-blocking), and [rate limiting](/docs/vercel-firewall/vercel-waf/rate-limiting). To enable it:

1. Open [your Blob store](https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fstores%2Fblob%2F%5Bstore%5D%2Fsettings\&title=Go+to+your+Blob+store) in the dashboard and select the **Settings** tab.
2. In the **Firewall** section, select **Protect your store**, then **Enable firewall**.

This connects your store to `vercel-blob-default-project`, a Vercel-managed project that holds the firewall rules for your team's Blob stores. The project is team-wide, so other stores that enable firewall protection reuse it and share its rules. After enabling, Vercel redirects you to the project's firewall page where you create your rules. To update them later, return to the store's **Settings** tab and select **Configure firewall**.

> **⚠️ Warning:** The **Challenge** action serves a JavaScript challenge that only a web
> browser can solve, so requests from the [Blob
> SDK](/docs/vercel-blob/using-blob-sdk) and other server-side code fail with a
> 429 response. Only use **Challenge** in rules that never match your
> application's SDK traffic.

The [OWASP core ruleset](/docs/vercel-firewall/vercel-waf/managed-rulesets#configure-owasp-core-ruleset) is not supported for Blob stores.


---

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