Step 2 — Sign Your Image

Everything runs in your browser. Your image and private key never leave your device.

1. Get Keys 2. Sign Image 3. Verify

Image Signed Successfully MetaImageUp computes three hashes of your image pixels (SHA-256, pHash, dHash), embeds an invisible watermark, bundles your name, email, and timestamp into a manifest, signs everything with your RSA private key, and writes all of this — plus XMP AI-rights flags — into the PNG file. The signed PNG is downloaded to your device. Nothing is uploaded.

Drop your image here

or paste from clipboard (Ctrl+V) · or click to browse

PNG JPEG WebP GIF

Your Identity

This information is embedded in the signed image and covered by the RSA signature. Anyone verifying the image will see this as the declared creator.

Full Name

Email Address

Signing Keys

Get Keys

Your private key is used only in your browser to compute the RSA signature. It is never transmitted or stored. This page has no network access to your keys.

Private Key (PEM) STAYS IN BROWSER

Paste the private key you downloaded from the Get Keys page.

Public Key (PEM)

Required so it can be embedded in the image for others to verify.

Optional Metadata

These fields are embedded in the signed manifest and visible to anyone who verifies the image.

Description

Location

What Gets Embedded

RSA-2048 Signature Computed from the full manifest (creator, hashes, timestamp, AI rights). Any change invalidates it.
Invisible LSB Watermark Hidden in blue channel pixels. Destroyed by screenshots, survives normal saves — used to detect re-capture.
SHA-256 + pHash + dHash Exact pixel fingerprint (SHA-256) plus two perceptual hashes that survive minor compression.
AI Rights Flags XMP block (read by Adobe Firefly) + ai_training=notAllowed PNG tEXt chunks + signed manifest assertion.
PNG Output — Always Lossless Output is always PNG regardless of input format. PNG preserves all metadata and pixels exactly.

A signed PNG will download automatically. Nothing is uploaded.

Step 2 — Sign Your Image

Your Identity

Signing Keys

Optional Metadata

What Gets Embedded

Image Signed Successfully

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