One-Time Links Explained: Security for IT Teams

One-time links (also called one-time secrets or ephemeral links) are a security mechanism for sharing sensitive information that self-destructs after being viewed. For IT teams handling credentials, API keys, and access tokens daily, understanding how these links work helps maintain security.

How one-time links work

The core principle is simple: create a link that can only be accessed once, then permanently destroy the content. But the implementation involves several security layers working together.

Step 1: Client-side encryption. When you create a secret, an AES-256-GCM encryption key is generated in your browser. Your data is encrypted locally before being sent to the server. The encryption key is added to the URL fragment (after the # symbol), which is never transmitted to the server.

Step 2: Server storage. The encrypted ciphertext is stored on the server along with metadata like expiration time and view count. The server only sees encrypted data and cannot read the original content.

Step 3: Client-side decryption. When the recipient opens the link, their browser extracts the encryption key from the URL fragment, fetches the encrypted data from the server, and decrypts it locally.

Step 4: Automatic destruction. After the allowed number of views, the encrypted data is permanently deleted from the server. Even if someone saved the link, it will no longer work.

Zero-knowledge architecture

The key innovation in modern one-time link services is zero-knowledge architecture. This means the server operator (including Burn the Secret) cannot access your secrets, even if compelled to do so.

This is achieved through the URL fragment mechanism. In web browsers, everything after the # symbol in a URL is never sent to the server. By placing the encryption key in the fragment, we ensure that:

• The server only stores encrypted, unreadable data
• Only someone with the complete link (including the fragment) can decrypt the content
• Server logs and database backups contain no useful information
• Even a server breach would not expose your secrets

Why IT teams need one-time links

IT teams face unique challenges when sharing sensitive information. Here are a few common scenarios where one-time links help:

Credential rotation. When rotating passwords or API keys, one-time links ensure the old credentials aren't sitting in email threads or chat histories.

New employee onboarding. Share initial login credentials securely without creating a permanent record that could be compromised later.

Vendor access. Provide temporary credentials to contractors or vendors without worrying about long-term exposure.

Incident response. During security incidents, share emergency credentials without adding to the communication trail.

Security considerations

While one-time links are significantly more secure than email or chat, there are still some things to keep in mind:

Link interception. If someone intercepts the link before the intended recipient, they can view and destroy the secret. Use passphrase protection for highly sensitive data.

Browser history. The complete URL (including fragment) may be stored in browser history. Recipients should use private/incognito mode for sensitive links.

Screenshot/copy. Once decrypted, the recipient can screenshot or copy the content. One-time links protect transmission, not what happens after viewing.

Implementing in your IT workflow

Here's how to integrate one-time links into your IT operations:

1. Create a policy: Define when one-time links should be used (always for credentials, API keys, etc.)
2. Use the API: For automated workflows, integrate with the Burn the Secret API to generate links programmatically.
3. Train your team: Ensure everyone understands why one-time links are important and how to use them.
4. Verify receipt: Establish a practice of confirming when credentials have been successfully retrieved.

Ready to start using one-time links? Create a secure link on Burn the Secret.