TL;DR: we’re adding 3 new features to KryptoSign today!

• CSV downloads of a document’s signers
• Document Locking (prevent further signing)
• Document Lotteries (pick a winner from list of signers)

Why? Well, you folks keep abusing this simple Ethereum-native document signing tool to run contests for airdrops and pre-sales, so we thought we’d make your lives a bit easier! :)

We launched KryptoSign in May this year as tool for Kai, Bart, and I to do the lightest possible “contract signing” using our MetaMask wallets. Write down a simple scope of work with someone, both parties sign with their wallet to signal they agree. When the job is complete, their Ethereum address is right there to copy-n-paste into a wallet to send payment. Quick, easy, delightful. :)

But as often happens, users started showing up and using it for other things. Like guestbooks. And then guestbooks became a way to sign up users for NFT drops as part of contests and pre-sales, and so on. The organizer has everyone sign a KS doc, maybe link their Discord or Twitter, and then picks a winner and sends a NFT/token/etc. to their address in the signature block. Cool.

As these NFT drops started getting really hot the feature you all wanted was pretty obvious: have folks sign a KS document as part of a pre-sales window, and have KS pick the winner automatically. Because the stakes on things like hot NFT pre-sales are high, we decided to implement the random winner using Chainlink’s VRF — verifiable random functions — which means everyone involved in a KryptoSign lottery can independently confirm how the random winner was picked. Transparency is nice!

The UI for doing this is quite simple, as you’d hope and expect from KryptoSign. There’s an action icon on the document now:

When you’re ready to pick a winner, it’s pretty easy. Lock the document, and hit the button:

Of note, to pick a winner we’re collecting to 0.05 ETH from you to cover the cost of the 2 LINK required to invoke the VRF on mainnet. You don’t need your own LINK and all the gas-incurring swapping that would imply. Phew! The user approves a single transaction with their wallet (including gas to interact with the smart contract) and they’re done.

Our initial users really wanted the on-chain trust of a VRF, and are willing to pay for it so their communities can trust the draw, but for other use cases you have in mind, maybe it’s overkill? Let us know! We’ll continue to build upon KryptoSign as long as people find useful things to do with it.

Finally, big props to our team who worked through some rough patches with calling the Chainlink VRF contract. Blockchain is weird, yo! This release saw engineering contributions from Neo Cho, Ryan Ouyang, and Josh Peters. Thanks!

— Mark

---

Celebrating 10k KryptoSign users with an on-chain lottery feature! was originally published in Block::Block on Medium, where people are continuing the conversation by highlighting and responding to this story.

https://medium.com/block-block/celebrating-10k-kryptosign-users-with-an-on-chain-lottery-feature-368e484df14b?source=rss-5c6a321cb3bd------2