What is sdbx?
sdbx is a zero-knowledge file sharing service designed with privacy as the core principle. Share files securely with end-to-end encryption, one-time downloads, and no user tracking.
Unlike traditional file sharing services, sdbx ensures that your files are encrypted before they leave your device, and the encryption key never reaches our servers. This means we literally cannot access your files, even if we wanted to.
Our Mission
In an age where privacy is constantly under threat, we believe that sharing files shouldn't require sacrificing your data or trusting a third party with your sensitive information.
sdbx was built to provide a simple, secure way to share files without:
- Creating accounts or providing personal information
- Trusting us with your encryption keys
- Worrying about files being stored indefinitely
- Being tracked or profiled
How It Works
🔐 Client-side Encryption
Your files are encrypted in your browser using AES-256-GCM before upload. We never see the unencrypted content.
🔑 Zero-Knowledge Architecture
The encryption key and original filename are stored in the URL fragment (#), which is never sent to our servers. Only you and the recipient have access.
🚫 No Tracking
No user accounts, no cookies, no analytics, no IP logging. We collect zero personal information.
⏱️ Self-Destructing Files
Each file can only be downloaded once, then it's automatically and permanently deleted from our servers.
Security Features
- End-to-End Encryption: AES-256-GCM with 256-bit keys generated in your browser
- HTTPS Only: All communication uses TLS 1.2+ encryption
- Bot Protection: Google reCAPTCHA v3 prevents automated abuse
- Atomic Operations: Database-level race condition prevention
- Origin Verification: CloudFront custom headers block direct API access
- Automatic Cleanup: Expired files are deleted hourly
Technology Stack
sdbx is built with modern, privacy-focused technologies:
- Frontend: Vanilla JavaScript, Web Crypto API
- Backend: AWS Lambda (Python 3.12), API Gateway
- Storage: Amazon S3 (encrypted files), DynamoDB (metadata)
- CDN: Amazon CloudFront
- Infrastructure: Terraform (Infrastructure as Code)
Limitations
To ensure optimal performance and security, sdbx has the following limitations:
- Maximum file size: 500 MB (0.5 GB)
- Files expire after 1, 12, or 24 hours (your choice)
- Each file can only be downloaded once
- Desktop browsers recommended for best experience
Privacy Policy
Simple version: We collect nothing.
- We don't store unencrypted files
- We don't store or have access to filenames
- We don't have access to your encryption keys
- We don't log IP addresses for file access
- We don't use cookies, tracking, or analytics
- Files are automatically deleted after first download or expiration
The only data we store is: encrypted file blobs (which we cannot decrypt), file size, upload timestamp, and expiration time. That's it.
Open Source
sdbx is open source and available on GitHub. We believe in transparency and invite security researchers to audit our code.
Disclaimer
This service is provided as-is. While we implement strong encryption and security practices, users are responsible for their own data. Do not use sdbx for illegal content.
For sensitive files, we recommend additional security measures like password-protecting archives before upload.
Questions?
Have questions, suggestions, or found a security issue?