Hash your file with SHA-256 and anchor it to Bitcoin via OpenTimestamps. Your proof will be verifiable forever — by anyone, without trusting Cypher Keep.
Any format, any size
OpenTimestamps batches your hash with thousands of others into a Merkle tree and commits the root to the Bitcoin blockchain. Your .ots file proves your content existed at this moment — verifiable by anyone, forever.
Your hash is pending Bitcoin block confirmation — typically 1–2 hours. The .ots proof file is your receipt. Keep it with your original file permanently. Verify anytime at opentimestamps.org.
Coming in next phases
Archive your content and confirmed .ots proof to the Arweave permaweb. One-time fee, stored forever. Transaction ID recorded in your Nostr event for a complete, permanent chain of custody.
Upload the original content (or its hash) and an .ots proof file to confirm the content is unaltered and existed at the claimed time. Fully local — no account needed.
Hash will be recomputed and compared to the proof
Generated when the content was originally stamped
Compute the SHA-256 hash of any file locally — then optionally compare it against an expected hash to confirm the file is unaltered. Nothing leaves your browser.
Any format · Hash computed locally · File never leaves your browser
Encrypt any file with a password using the age encryption format — an open standard decryptable with any age-compatible tool, forever, independent of Cypher Keep. Everything runs locally in your browser.
If you lose your password, the file cannot be recovered by anyone — including us. There is no reset. Write it down and store it somewhere safe before you proceed.
Any format · Encrypted entirely in your browser
Share the .age file freely. Send the password separately — never in the same message.
The recipient can decrypt it here, or with any age-compatible tool — no Cypher Keep required.
Encrypted with Cypher Keep or any age-compatible tool
Your file has been decrypted and is ready to download.
Incorrect password, or this file was not encrypted with age. Check the password and try again.
Your Cypher Keep stamps posted to Nostr, queried live from public relays. Each entry links to the permanent Nostr event carrying your hash and pending OTS proof.