
Treepoints
Wren
YAYZY
Capture
Ecosia
Kuri
Aerial
Carbon Neutral Club
BlockchainSign
OriginStamp
ScoreDetect
Woleet
Stampery
Bitstamped
Certificado
Proof of existence
BlockchainSign is a blockchain timestamping service for people holding documents they cannot hand over.
Conventional options all require custody: a copyright office wants a deposit copy, a notary wants to see the paper, an e-signature platform wants the file on its servers. BlockchainSign never receives the file at all. The document is hashed with SHA-256 in the user's own browser using the Web Crypto API, and only the resulting hash is written to the Ethereum blockchain.
The result is a certificate file recording the hash, the transaction and the timestamp. Because each certificate is its own Ethereum L1 transaction, with the payload hash readable as UTF-8 on a public block explorer, verification does not run through the vendor's portal: if BlockchainSign shut down, existing certificates would still verify.
There is no subscription and no cryptocurrency wallet involved. Certificates are bought as credits with a card and spent when needed. Credits are valid for 12 months; an issued certificate never expires.
Key points
What it does not do. A timestamp proves that a file existed in that exact form at that time โ existence and integrity. It does not prove authorship or ownership, and it is not a substitute for copyright registration. There is no API or integrations yet, and no eIDAS qualified timestamp.
Treepoints
BlockchainSignBased on our record, Treepoints seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
We're several months into running this business and just launched it on producthunt (all info is there and on our website: https://treepoints.green and https://www.producthunt.com/posts/treepoints). Source: about 5 years ago
Wren - Offset your carbon footprint by saving rainforests
OriginStamp - Blockchain-based, tamper-proof timestamping. Data Integrity as a Service.
YAYZY - Track the carbon footprint of each purchase in real-time
ScoreDetect - ScoreDetect is an innovative platform that serves as a permanence layer for data provenance, enabling systems and authorities to independently verify data authenticity.
Capture - A great free screen capture utility that allows you to capture either a window or the desktop and save it to either a file or the clipboard.
Woleet - Blockchain timestamping and certification Software as a Service , SaaS.