2026-08-23 timestamp git blockchain proof

Proof of Existence in Software: A Beginner’s Guide

What does it actually mean to prove that a piece of software existed at a specific moment? If you have ever needed to show “I built this before you did” without revealing your source code, the answer lies in a concept called proof of existence. This guide explains the idea, clears up common misconceptions, and shows how Timestamp GIT turns it into a zero-setup GitHub App.

What Is Proof of Existence in Software?

Proof of existence is cryptographic evidence that a specific piece of digital data existed at a specific point in time. In software, that data is usually a Git commit hash. The process works by:

Creating a one-way hash of the data — a cryptographic fingerprint.
Anchoring that fingerprint in an immutable public ledger, the Bitcoin blockchain.
Storing a receipt that lets anyone verify the anchor independently.

Unlike internal logs, emails, or ordinary version-control timestamps, cryptographic proof does not depend on one person or server being honest. The evidence lives in Bitcoin’s public blockchain, where the math can be checked by anyone.

Proof of existence is also a key tool for establishing prior art in intellectual property disputes. If a patent troll claims your technique, a Bitcoin-anchored timestamp can show that you already had the implementation months or years earlier.

A Simple Analogy: The Notary Public for Your Code

Think of a traditional notary. You sign a document, the notary watches, and then stamps it with an official seal and date. Later, anyone can look at the stamp and know the document existed on that date.

Proof of existence does the same for digital data:

Fingerprint — Your Git commit hash is a unique fingerprint of your exact repository state at that moment.
Anchor — The fingerprint is recorded in the Bitcoin blockchain, like a notary’s official register.
Proof — You receive an .ots receipt file, like a notarized certificate that anyone can verify.

The key difference: nobody has to trust the notary’s server or database. Bitcoin’s public ledger makes the record immutable.

How It Works Under the Hood (Briefly)

Under the hood, proof of existence for software follows three steps:

Fingerprint — Git generates a one-way hash of the exact repository state. That hash is the commitment.
Anchor — Timestamp GIT extracts only the commit hashes, batches them daily, and creates a Merkle tree. The Merkle root is then anchored into a Bitcoin transaction using the OpenTimestamps protocol.
Proof — Once the Bitcoin block is confirmed, you receive an immutable .ots receipt file. Anyone can verify it using standard OpenTimestamps verification tools against the Bitcoin blockchain.

Here is what a commit hash looks like locally:

# Your Git commit hash is a one-way fingerprint of the full repository state
git rev-parse HEAD
# Example output: 7c2f0a9b3e8d4f1c6a5b9c0d1e2f3a4b5c6d7e8f

Timestamp GIT automates this entire pipeline. You install the GitHub App once, and every commit to a monitored repository is fingerprinted and anchored automatically each night. There are no CLI tools, no manual OpenTimestamps commands, and no Bitcoin wallet setup. The product is a managed service that hides the protocol behind a GitHub integration.

Zero-knowledge is built in: Timestamp GIT never sees, copies, or stores your source code. It only processes commit hashes. In Enterprise ZK mode, even the commit hash is pushed from your own infrastructure by a GitHub Action, so no read access to the source repository is required.

Verification is independent. You can download the .ots receipt and verify it against the Bitcoin blockchain yourself, even if Timestamp GIT disappears.

Why Proof of Existence Matters: Common Misconceptions

Misconception 1: “My Git history is enough.”

Git history is useful for development, but it lives on servers you do not fully control. Git commits can be rewritten, dates can be changed, and internal logs are often dismissed in legal audits as self-serving or manipulatable. Proof of existence anchors a hash in a public blockchain, making the timeline mathematically verifiable.

Misconception 2: “I need to publish my code to prove prior art.”

No. The fingerprint is a one-way hash. Timestamp GIT never sees your source code, and the proof does not reveal it. You can establish prior art without publishing your code or filing public documents.

Misconception 3: “Blockchain timestamps are only for cryptocurrency.”

Bitcoin’s primary value for software developers is not currency. It is an immutable, public ledger. The same properties that prevent double-spending also make Bitcoin ideal for timestamping any digital data. Your proof is embedded in Bitcoin block data, making it globally verifiable and permanent.

Real-world scenarios where proof of existence matters:

Defending against patent trolls by showing you implemented a technique before a patent filing
Proving when a feature was conceived in an employee dispute
Establishing clean-room development timelines when a competitor claims independent invention
Protecting trade secrets without publishing them

How to Get Proof of Existence for Your Code with Timestamp GIT

Here is the primary workflow:

Install the Timestamp GIT GitHub App on your repository. This is a one-time setup.
Keep committing as usual. The GitHub App detects new commits automatically via webhooks.
Each night, Timestamp GIT batches your commit hashes, creates a Merkle tree, and anchors the Merkle root into the Bitcoin blockchain.
Proofs are delivered to a dedicated branch or shadow repository. You can display a verification badge in your README to show that your commits are anchored.

# After installing the GitHub App, your normal workflow is unchanged
git add .
git commit -m "Add proof-of-existence example"
git push origin main

If you need maximum isolation, Enterprise ZK mode runs a GitHub Action on your infrastructure that pushes only the commit hash to the Timestamp GIT API. Zero code access means your source never leaves your environment.

For air-gapped or regulated environments, Timestamp GIT is also available as a Docker self-hosted image. That lets you run the same automation inside your own infrastructure.

FAQ

What is the difference between proof of existence and proof of authorship?

Proof of existence establishes that a specific digital artifact, like a Git commit hash, existed at a certain time. Proof of authorship additionally ties that artifact to a specific person or entity. Timestamp GIT provides proof of existence; authorship can be inferred from the repository and commit metadata.

Can proof of existence be verified without trusting Timestamp GIT?

Yes. The proof is based on the OpenTimestamps protocol and the Bitcoin blockchain. You can download the .ots receipt and verify it independently using standard OpenTimestamps verification tools against the Bitcoin blockchain. Timestamp GIT does not need to be involved in verification.

Does proof of existence require revealing my source code?

No. Timestamp GIT only processes Git commit hashes, which are one-way fingerprints. Your source code never leaves your repository. In Enterprise ZK mode, even the commit hash is pushed from your infrastructure, ensuring zero code access.

How long does it take to get a proof after a commit?

Timestamp GIT batches commits daily and anchors them into the Bitcoin blockchain. The confirmation typically takes a few hours after the daily batch. You receive the .ots receipt once the anchor is confirmed.

How much does Timestamp GIT cost?

Timestamp GIT offers an Open Source plan for public repositories, a Pro Agency plan for private repositories, and an Enterprise ZK plan for GitHub Actions-based zero-knowledge mode. A Docker self-hosted license is also available for teams that need to run the service on their own infrastructure.

What if I want to verify a specific commit’s timestamp?

Timestamp GIT provides a public dashboard for each monitored repository, including longevity, anchor dates, Bitcoin block data, and downloadable audit CSV and PDF certificates. You can also use the API endpoints for status, verification, and reports. For a deeper walkthrough, see the related article on verifying Git commit timestamps.

Conclusion

Proof of existence in software is not magic. It is the combination of a one-way fingerprint, an immutable public ledger, and an independently verifiable receipt. The traditional alternatives — Git logs, server timestamps, and email trails — are weak in a legal context. A Bitcoin-anchored proof is mathematically much stronger.

Timestamp GIT turns this concept into a product you can install once and forget about. The GitHub App watches your repository, batches commit hashes at night, and returns .ots receipts without ever reading your source code. If you want to prove when your code existed, install Timestamp GIT and connect your repository.

Proof of Existence in Software: A Beginner's Guide