Client-Side Sanitization: Why Metadata Must Never Leave Your Browser
Exploring browser-based binary parsing: how HTML5 File APIs and typed arrays strip identifying device fingerprints and location tags before network transmission.
Server-Side vs. Client-Side Scrubbing
Many privacy tools claim to 'strip metadata,' but require you to upload the raw file to their servers first. In this server-side model, your ISP, intermediate proxies, and the platform operator still receive your unscrubbed GPS location before the server removes it.
True privacy requires client-side sanitization: stripping identifying markers within your device's browser memory before any network packet is dispatched.
Key Architectural Takeaways
- Server-side scrubbing still exposes raw location data to server operators and proxies.
- HTML5 ArrayBuffer and DataView APIs allow in-memory binary inspection on client devices.
- Only sanitized raster data is uploaded, ensuring zero upstream data leakage.
Binary Parsing in JavaScript
Locky uses native JavaScript typed arrays (Uint8Array and DataView) to inspect file byte signatures. For JPEG images, the binary parser searches for the 0xFFE1 marker (APP1 segment) containing the EXIF TIFF header.
The algorithm constructs a new binary buffer containing the image payload while omitting the APP1 block. This operation executes in less than 50 milliseconds directly in the browser.
Device Fingerprint Elimination
Beyond GPS coordinates, EXIF tags store camera serial numbers, lens IDs, firmware versions, and thumbnail caches. Scrubbing these segments eliminates unique hardware fingerprints that forensic investigators use to link multiple photos to a single physical device.
Try Zero-Knowledge Ephemeral Sharing
Need to share a photo or video privately without permanent digital footprint? Locky strips location metadata client-side in your browser, locks media behind a 4-digit numeric PIN, and guarantees automatic self-destruction in 24 hours.
Related Knowledge Base Guides
EXIF Metadata & Geotags: What Photos Reveal About Your Location
A deep dive into Exchangeable Image File Format (EXIF) data, GPS latitude and longitude tracking, and why client-side metadata sanitization is critical before sharing photos online.
Ephemeral StorageThe Dangers of Permanent Cloud Links: Why 24-Hour Self-Destruct Protects You
Why traditional cloud drives like Google Drive and Dropbox create persistent security vulnerabilities, and how automated ephemeral lifecycles eliminate link-rot and data leaks.