Cefrium keysigning companion

OpenPGP fingerprint exchange, running on Cefrium — native CEF on Android. The system WebView has no Web NFC and no camera barcode access like this.

Collect fingerprints

Scan a person's QR, or tap their tag. Uniques accumulate below.

Collected: 0

Verify before you sign. A QR/tag only loads a candidate fingerprint. Check the person's ID and confirm this fingerprint against their slip before running caff.

Export

Share sends the caff line to email / messaging so you can run it on your laptop. The command and fingerprints are public.

Program a giveaway tag

Writes your OPENPGP4FPR + a keyserver URL to an NTAG. Lock it so it can never be overwritten.

Unlocked tags are rewritable by anyone. For tags you hand out, use Write + lock (makeReadOnly) so the content is permanent. The QR tab needs no tag at all.

Keysigning, in a minute

To trust an OpenPGP key, others sign it after confirming it really belongs to you. Their signatures build the web of trust (and get your key into the Debian keyring). This app speeds up the part where you exchange fingerprints.

What it replaces

The old wayPrint paper slips with your 40-hex fingerprint, read it aloud, everyone transcribes it by hand -- typo-prone and slow.

With CefriumShow a QR or tap a tag. The exact fingerprint is captured with zero transcription. (WebView can do neither.)

The flow

1. Show — your fingerprint as a live QR (Share), or hand out a written NFC tag (My tag).

2. Capture — the other person scans your QR with their camera, or taps your tag (Collect). Repeat for everyone.

3. Verify in person — they check your government photo ID and confirm the captured fingerprint is really yours. This is the trust step.

4. caff — on their laptop they run caff <fingerprint> (Export shares the command). It fetches your key from the keyserver and signs that copy.

5. Trust grows — the signature is published; your key gains a verified link in the web of trust.