Why a Hash Cannot Reveal Your File

A hash is not encryption. It is a one-way mathematical digest. There is no “key” to turn a hash back into a document. Publishing a hash inside a Bitcoin transaction does not expose the document. It only proves the document existed at or before the block time if you can later show the same file that reproduces the hash.

Energy Reality: Brute Forcing SHA-256 Is Physically Impractical

Breaking SHA-256 by brute force means searching a space of size 2²⁵⁶ for a specific preimage. Even a collision attack targets about 2¹²⁸ work on average. These numbers are astronomical.

• Lower bounds from physics: Even if a hypothetical computer ran at the thermodynamic limit for bit operations, the energy needed to brute force would exceed practical planetary energy budgets by extreme margins.
  
• Real hardware limits: Actual chips are many orders of magnitude less efficient than those theoretical limits. Scaling to meaningful fractions of 2¹²⁸ or 2²⁵⁶ operations would require energy and time that cannot be supplied by nations, let alone attackers.
  
• Economic reality: The cost to attempt meaningful fractions of these searches would dwarf any rational payoff.

Conclusion: brute forcing SHA-256 to forge a timestamped proof is not a viable path. It is effectively impossible under known physics and economics.

AI Is Not a Threat to the Hash or the Chain

AI can generate convincing fakes, but it does not change the math behind SHA-256 or the consensus rules of Bitcoin.

AI cannot “guess” preimages for 256-bit hashes or rewrite confirmed Bitcoin history. AI may help people produce forgeries, but those forgeries will fail verification against the original hash.

Quantum Computing: What Changes and What Does Not

Shor’s algorithm threatens some public-key systems. It does not give an exponential speedup against hash preimage problems.

• Grover’s algorithm offers a quadratic speedup for unstructured search. For SHA-256 preimages that reduces effective security from 256 bits to about 128 bits.
  
• 128-bit preimage security remains far beyond reach using any plausible quantum hardware scale, stability, and error-correction known today.
  
• Hashing can scale: If future conditions ever warranted it, schemes can incorporate multiple rounds or larger digests to restore comfortable margins. Hash-based proofs have straightforward upgrade paths.

Bottom line: practical quantum machines, if achieved, do not make reversing a strong hash easy. The proof model remains robust.

Bitcoin Anchoring: Independent, Global, and Durable

The time-binding process anchors a single root hash into the Bitcoin blockchain using a data field in a transaction. This gives a public, independently auditable timestamp.

What the Blockchain Is

Bitcoin is a public ledger maintained by a decentralized network of nodes that follow strict rules.

Transactions are grouped into blocks.

Miners expend real-world energy to find a valid block header under a difficulty target.

Each block references the previous block, forming a chain.

Rewriting history means redoing that work faster than the rest of the world, which is economically prohibitive.

How Anchoring Works

• Your files are hashed locally in your browser.
• Those file hashes and optional metadata hashes are combined into a single Merkle root.
• That root is placed into a Bitcoin transaction’s data field and mined into a block.
• Anyone can later verify that root exists at or before that block’s time, then re-hash your file locally and confirm it matches.

This gives you a permanent, public proof of existence without exposing the file itself.

Your Files Never Leave Your Device

Hashing happens in your browser. The file contents are not uploaded. Only the resulting hashes and necessary anchoring references are handled by the service. Since the original documents never transit to servers, they cannot be leaked or compromised by the service.

Why a Published Hash Does Not Leak the Document

Publishing the hash on Bitcoin does not reveal anything about the file beyond its existence at a point in time. There is no way to reconstruct the file from the hash. The hash does not act like a key. It is safe to publish and share for verification.

Protected Forever: Verification That Outlives Systems

The proof does not depend on TimeBinder’s servers for trust. The anchoring reference sits on the public Bitcoin ledger. Anyone can:

• Obtain the original file from you.
  
• Hash it locally using standard tools.
  
• Check that the resulting digest is committed in the historical Bitcoin chain at or before a block time.

As long as the Bitcoin ledger remains accessible, the proof remains verifiable. Historical copies of the chain are widely replicated. Even if software stacks change, the ledger and the simple act of recomputing SHA-256 stay available. Learn more about our verification process here.

Threat Model Summary

• Reverse engineering the file from the hash: Not possible. Hashing is one-way.
  
• Forging a file to match a published hash: Requires breaking SHA-256 preimage resistance. Computationally and energetically infeasible.
  
• Creating a different file with the same hash: Requires a practical collision. No such attacks exist for SHA-256. Work factor is beyond feasibility.
  
• Rewriting the blockchain to remove or backdate a proof: Requires out-hashing the global network’s cumulative proof of work. Economically infeasible.
  
• AI-assisted forgery: Fakes will not match the original hash and will fail verification.
  
• Quantum computing: Does not make reversing SHA-256 easy. Grover’s quadratic speedup still leaves prohibitive costs at 128-bit effective security.

End-to-End Privacy and Control

You control the document and when it is shared for verification.

The published anchor contains no readable content and no personal data from the file. Verification can be done privately by the parties who hold the file without exposing it to anyone else.

Why This Is the Only Practical Way to Secure Document Timing

To beat this model an attacker must either reverse a strong hash or economically out-compete the global Bitcoin network. Both are outside practical reach.

Traditional methods like email timestamps, local file metadata, or private databases can be edited or forged.

Public, energy-secured consensus and one-way hashing remove those weaknesses and provide independent, permanent verification.

Key Takeaways

• Your files are hashed locally. They never leave your device.
  
• Hashes are one-way and do not reveal file contents.
  
• Brute forcing SHA-256 would require impossible energy and time.
  
• AI cannot reverse hashes or rewrite Bitcoin history.
  
• Quantum does not break SHA-256 preimage security in practice.
  
• Anchoring on Bitcoin gives independent, permanent proof of existence.