PROXAE

Use case

Prove a document was sent

To prove a document was sent with specific content, you need to certify its existence before sending. Proxae creates a timestamped proof in the Bitcoin blockchain — proving content existed at a given date, regardless of receipt.

Need to prove you sent a document on a specific date? Certify its existence before sending — this is proof that the content existed at that moment.

Certify a document →

The problem

An email can be challenged. A delivery receipt proves delivery, not content. To establish that the exact document existed before a certain date, you need an independent timestamp.

Real-world examples

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A lawyer certifies a formal notice before sending — proof that the exact document existed at that date, regardless of receipt.

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A provider timestamps a quote before sending it to the client — in case of dispute over terms, the content is proven.

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An employee certifies a whistleblower report before submitting it to management — traceability in case of inaction.

The Proxae solution

1

Certify the document

Before sending, upload the file to Proxae. The SHA-256 fingerprint is generated in your browser.

2

Send as usual

Send the document by email, post, or platform. You now have proof that this exact content existed on that date.

3

Verification when needed

If the content is disputed, re-hash the sent document. If the hash matches your Proxae proof, it is irrefutable.

Before sending an important document, certify its content. 10 seconds, free, irrefutable.

Certify a document

Proxae vs certified delivery methods

Proxae Registered mail w/ AR Certified email
Cost ✓ Free $5-10 $3-5
Speed ✓ Instant 2-5 days Instant
Privacy ✓ Full (local hash) Document sent Via third party
Permanence ✓ Permanent (Bitcoin) Proof of receipt Depends on provider

Concrete use cases

  • ✦ Formal notices — prove the content sent
  • ✦ Quotes and proposals — officially date them
  • ✦ Reports and deliverables — track versions
  • ✦ Legal notifications — complement the delivery receipt

Frequently asked questions

Does this prove the document was received?
No. Proxae proves the document existed at a given date. To prove receipt, combine with a delivery receipt or registered mail.
What happens if the document is modified afterwards?
The slightest change alters the SHA-256 hash. If the recipient modifies the document, the hash will no longer match the proof — which proves the modification.
Can I use URL capture to certify an email?
URL capture works for public web pages. For an email, certify the exported PDF file of the email instead.
What is the difference with an acknowledgment of receipt?
An acknowledgment of receipt proves delivery, not content. Proxae proves the exact content existed at a given date. Both are complementary — combine them for complete proof.
Can the recipient verify the proof?
Yes. Share the link to your Proxae proof. The recipient can recompute the hash of the received document and verify it matches — proof the content was not modified.
Certify a document

Before sending, prove it.