BitSplit Media Delivery

説明

BitSplit changes how WordPress delivers public images. Instead of keeping a
complete image at a stable public URL, it stores the original and generated sizes
as incomplete blocks and reconstructs each image in the visitor’s browser through
a short-lived session.

It is an image-protection layer for photography portfolios, publishers, member
sites, and other WordPress sites where making direct downloads and bulk collection
harder is valuable.

Learn more at bitsplit.site.

Why use BitSplit?

• No stable ready-to-download image URL – public image paths serve incomplete
  blocks rather than finished image files.
• Normal WordPress workflow – use the Media Library, Gutenberg Image and
  Gallery blocks, featured images, and responsive srcset markup as usual.
• Two access modes – keep images public while adding download friction, or
  require visitors to sign in before reconstruction.
• No external service – reconstruction runs on your WordPress site and in the
  visitor’s browser, with no SaaS account, license key, quota, or payment.
• Backup and recovery tools – export a recovery manifest before site changes
  and restore attachment mappings when needed.

BitSplit is not encryption, DRM, or a promise that downloading is impossible.
A determined viewer can inspect the browser flow, automate reconstruction, or
capture rendered content. Use it when raising the cost of casual downloading is
valuable; use established encryption and access control when confidentiality is
required.

Included functionality

The plugin protects any number of image attachments. All image functionality
shipped in this WordPress.org package is available without payment, a license,
a trial, or a usage quota.

It includes public or logged-in-only access, Gutenberg image support,
featured-image and srcset handling, and backup/recovery tools.

Delivery flow

1. WordPress stores each image as an incomplete BitSplit block, with reconstruction
   data stored separately in attachment metadata.
2. Front-end image markup receives a placeholder instead of the original image URL.
3. The browser establishes an ephemeral P-256 ECDH session.
4. Reconstruction data is transported with HKDF and AES-256-GCM.
5. Block bytes require a short-lived, session-bound signed token.
6. The browser reconstructs the image into a temporary Blob URL.

The transport encryption protects reconstruction data in transit; the BitSplit
block itself is not encrypted and contains most source bytes.

Access modes

• Public visitors – public images remain viewable; BitSplit adds download and
  scraping friction.
• Logged-in users only – anonymous visitors cannot obtain reconstruction data
  or block bytes.

WordPress coverage

BitSplit handles normal attachment images, Gutenberg Image and Gallery blocks,
featured images, srcset, classic content containing wp-image-ID, and the
[bitsplit id=”123″] shortcode.

Storage

Incomplete blocks are stored in a plugin-owned directory resolved through
wp_upload_dir(), while reconstruction data stays in WordPress post metadata.
The plugin does not write web-server configuration files or require users to edit
server configuration.

Requirements

• PHP 7.4 or newer
• GMP extension
• OpenSSL with ECDH support