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Measured on six things

Private, dated proofs of data on the BitcoinZ blockchain.

Speed

Lighthouse mobile 49/100 with a 9.4s LCP and 684ms TBT; desktop 72/100. The GitHub page itself is heavy, and each proof is stated to take 10-60 seconds on-chain, so perceived speed is slow end to end.

Screenshots

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ZKStamp Proof-100

About this app

ZKStamp Proof-100 is a fascinating and somewhat niche tool that writes the SHA-256 fingerprint of any file to the BitcoinZ blockchain inside a shielded (zk-SNARK) transaction. You get a dated proof that the file existed, and nobody on the blockchain can see the fingerprint or who made it. The process is simple: you send a 64-hex-character fingerprint, the server embeds it in an encrypted memo sent to a brand-new shielded address, and you receive the transaction ID and viewing key. Later, you can verify the proof with ZCheck, a small Python script that reads the fingerprint directly from the blockchain on your own BitcoinZ node. The service also exposes an MCP endpoint for AI agents, allowing them to timestamp fingerprints or text programmatically. A pack of 100 proofs costs 500,000 BTCZ (about 5,000 BTCZ per proof), and new accounts get 3 free trials. The proof itself is designed to be quantum-resistant in terms of the SHA-256 fingerprint and date, though the privacy relies on curre...

Key features

1Writes SHA-256 fingerprints into shielded zk-SNARK memos on the BitcoinZ blockchain for private, dated proof of existence.
2ZCheck Python script verifies proofs directly from a synced BitcoinZ node using txid and viewing key.
3MCP endpoint at /mcp exposes timestamp_fingerprint, timestamp_text, and check_balance tools for AI agents.
4No-account pricing: 500,000 BTCZ for 100 proofs, 3 free trial proofs per new account.

Target customer profile

Drawn from the product itself, not from a survey.

Demographic

Crypto enthusiasts and BitcoinZ holders

Pain points

Need a private way to prove data existed without exposing content.

Primary needs

A cheap, blockchain-based timestamping service with shielded transactions.

Demographic

AI agent developers

Pain points

Agents require a programmatic, private proof-of-existence tool.

Primary needs

MCP-compatible API for timestamping fingerprints and text.

Demographic

Journalists and whistleblowers

Pain points

Risk of exposure when proving document authenticity.

Primary needs

Anonymous, encrypted proof of existence with selective disclosure.

Scout Review

Written by AI from measured evidence, scored out of 100.

ZKStamp Proof-100 is a niche but coherent product: it writes SHA-256 fingerprints into shielded BitcoinZ transactions so you get a dated, private proof of existence, verifiable with the ZCheck script. The README is unusually honest about limits, the security headers are solid, and the MCP endpoint for AI agents is a smart modern touch. The weaknesses are real: the live page is GitHub's default layout, mobile performance is poor (LCP 9.4s), there's no GUI or dashboard, and no third-party security validation. It's a developer tool for a small audience, and it knows it.

Measure by measure

Usability

Copy-ready curl commands, explicit no-account pricing, and a candid 'honest limits' section make onboarding clear for developers. The MCP setup for Claude is documented step by step. Lacks a hosted dashboard or GUI.

Design

The README is well-structured with clear hierarchy, numbered steps, and monospace tokens, but the live page is GitHub's chrome, not a designed product surface. The promo card's stamp motif is on-brand yet the hex texture reads as noise.

Speed

Security

Strong header hygiene: HTTPS, HSTS, CSP, frame protection, secure cookies, SPF and DMARC all present (12/13). Shielded zk-SNARK memos with per-proof viewing keys are a real privacy design. No SOC 2, pen-test, or bug bounty published.

Accessibility

Lighthouse accessibility 97/100 with only two failing audits: touch target sizing and label/name mismatches. No a11y statement or multi-language support published, but the core page is highly readable and keyboard-friendly.

Growth

A real problem with a specific wedge: shielded proofs on BitcoinZ plus an MCP endpoint for AI agents. Differentiated from OpenTimestamps and OriginStamp on privacy, but the BitcoinZ-only bet caps the addressable market.

Improvement areas

No hosted dashboard or GUI; onboarding requires curl commands and manual key management.
No published security audits, pen-test reports, or bug bounty to back the privacy claims.
Mobile performance is poor (LCP 9.4s, Lighthouse 49/100) on the GitHub-hosted page.
BitcoinZ-only bet caps the addressable market versus multi-chain competitors.

Design & Usability

Design is the weakest surface: the live page is GitHub's default repo layout, so the maker's identity lives only on a promo card and the README. That README is actually well-crafted, with clear hierarchy, numbered how-it-works steps, and monospace tokens that keep technical strings readable. Usability is stronger: copy-ready curl commands, an explicit no-account pricing model (500,000 BTCZ for 100 proofs, 3 free trials), and a refreshingly honest 'trust model and honest limits' section that names server outages and quantum risk. The MCP setup for Claude is documented step by step. What's missing is a hosted dashboard or GUI, so non-developers are effectively locked out.

Speed & Security

Speed is the sore spot: Lighthouse mobile 49/100 with a 9.4-second LCP and 684ms TBT, desktop 72/100. The GitHub page is heavy, and each proof is stated to take 10-60 seconds on-chain, so the end-to-end experience is slow by design. Security is the strongest dimension: HTTPS, HSTS, CSP, frame protection, secure cookies, SPF and DMARC all present (12/13 checklist points), with only Permissions-Policy missing. The shielded zk-SNARK memo design with per-proof viewing keys is a genuine privacy architecture, not marketing. The gap is third-party validation: no SOC 2, no pen-test report, no bug bounty published, which for a service handling paid crypto deposits is a real trust gap.

Accessibility & Growth

Accessibility scores 97/100 on Lighthouse with only two failing audits: touch target sizing and label/name mismatches. No a11y statement or multi-language support is published, but the page is readable and keyboard-friendly. Growth is a judgement call on the idea: Proof-100 names a real problem (private proof-of-existence) and has a specific wedge against OpenTimestamps and OriginStamp, namely shielded transactions on BitcoinZ plus an MCP endpoint for AI agents. That wedge is genuinely differentiated, but the BitcoinZ-only bet caps the addressable market hard. Repo traction is early (0 stars, 15 commits), which is context, not the score.

Conclusion

If you're a BitcoinZ holder or an AI agent developer who needs private timestamping and can live with curl commands, Proof-100 delivers exactly what it promises with refreshingly little hype. If you want a polished SaaS with a dashboard, SOC 2 badge, and sub-second UX, this isn't it. The honest-limits section is the most trustworthy thing on the page, and that's both a compliment and a warning: the product is small, early, and betting everything on one chain.

Suggestions for improvement

Ship a minimal hosted dashboard so non-developers can create and verify proofs without curl.
Publish a security page with a pen-test summary or bug bounty to back the privacy claims.
Fix the mobile LCP (9.4s) by trimming the GitHub page weight or hosting a lightweight landing page.
Add an accessibility statement and fix the two failing Lighthouse audits (touch targets, label names).

How we score

Alternatives comparison

Named competitors, point by point. Nobody paid to appear here or to be left out.

	ZKStamp Proof-100	OpenTimestamps	OriginStamp
Blockchain used for timestamping	BitcoinZ (shielded zk-SNARK transactions)	Bitcoin (via OpenTimestamps calendars)	Multiple chains (Bitcoin, Ethereum, and others)
Privacy of the proof	Fingerprint hidden in shielded memo; per-proof viewing key	Hash aggregated into Bitcoin tx; content private, timing public	Hash on-chain; less privacy focus per description
Pricing model	500,000 BTCZ for 100 proofs (~5,000 BTCZ each); 3 free trials	Free and open-source	Paid tiers with API access
API / programmatic access	REST API plus MCP endpoint for AI agents	Open-source CLI and libraries	REST API access
Verification method	ZCheck Python script on own BitcoinZ node with txid + viewing key	OpenTimestamps client verifies against Bitcoin chain	Web portal and API verification