Now taking Worldbuilders donations via Ether!


We previously wrote about the amazing charity Worldbuilders, and encouraged the Ethereum community to contribute to this year’s fundraiser. The fundraiser’s still got a week to go, and we’ve got good news: we’ve set up an Ethereum address for donations in Ether.

As of now, you can donate in Ether to address 0xf1bD45D022d31B04341714D6fADA81CCe7cE3717. Before the end of the fundraiser, all the funds raised will be converted to fiat, and donates to Worldbuilders via the Ethereum team page. Donations will be eligible for the same gift matching as regular fiat donations. If the fiat conversion donation wins any prizes in the Worldbuilders lottery, we’ll work out a fair protocol for doing a lottery drawing of contributions to the above address, and post the winning addresses on Reddit so the winners can identify themselves.

Just like with fiat donations, we’re doing our small part to try and encourage people to donate: We’ll send a free Ether Card, anywhere in the world, to anyone who donates at least 2 ether to Team Ethereum for Worldbuilders this year. Email [email protected] with an your transaction ID and an address and we’ll send a card out to the person of your choice as a thank you for supporting this amazing charity.

The fundraiser ends December 20, so we don’t have a lot of time - let’s continue to show people how awesome the Ethereum community can be.

Support Worldbuilders and get a free Ether Card


Worldbuilders is a charity run by one of our favorite authors, Patrick Rothfuss with an incredible goal: to raise funds for Heifer International, who provide livestock and training to disadvantaged families, providing them with the ability to become self-sustaining and independent.

Each year in December, Worldbuilders raise hundreds of thousands of dollars for Heifer. Some incredible authors get involved and donate stuff - mostly books - to a lottery, and everyone who donates at least $10 has a chance to win something from the lottery.

We think it would be awesome if the Ethereum community showed how generous they are by helping out a bit, so we’ve worked with Worldbuilders to set up a team page, where any donations to the fundraiser are attributed to the Ethereum community. Right now, only fiat donations are accepted, but we’re working with the Worldbuilders team to get them set up with an Ethereum wallet so they can take donations in Ether, too. We’ve got some neat ideas on how to make that even cooler with giftmatching contracts, and we’d love to hear your ideas along those lines too.

Finally, we’re doing our small part to try and encourage people to donate: We’ll send a free Ether Card, anywhere in the world, to anyone who donates at least $10 to Team Ethereum for Worldbuilders this year. Forward a copy of your receipt to [email protected] with an address and we’ll send a card out to the person of your choice as a thank you for supporting this amazing charity.

The fundraiser ends December 9, so we don’t have a lot of time - let’s show people how awesome the Ethereum community can be.

Holiday designs now available


We’re pleased to announce that the two winning holiday designs are now available for preorder! The winning designs were the ‘Ethereum Xmas Tree’:

and the Ethereum Snowflake:

We expect to ship orders for these seasonal designs starting November 28, and they’ll be available only until the new year, or until we run out of stock, so preorder yours now.

Holiday designs for Ether Cards!


We’ve been working hard on holiday designs for Ether Cards, and we’ve got a few candidates we’d like your feedback on. See the poll below, and let us know which you think are the most interesting!

Our guarantee


Every Ether Card produced comes with this guarantee:

If you can present an Ether Card with untouched scratch panel, but whose account has an outgoing transaction, or a card whose private key is incorrect or unreadable through no fault of your own, we will refund the lost funds, up to a total value of 5 ether, from our guarantee account. This guarantee is valid for one year from the date of manufacture of each card.

That means that if someone else somehow spends your funds before you scratch off the private key, or you scratch it off and find the key is unusable (for example, due to a printing error), we will refund any losses up to a maximum of 5 ether.

If you’ve already scratched the panel, we can’t refund you for any unexpected withdrawals, because there’s no way to verify how the transaction happened. Likewise, if you use sandpaper on your private key, feed it through a shredder, drag it behind a car, or give it to your dog, we can’t be held responsible for any losses due to the key becoming illegible.

The guarantee account is funded by a deposit of 0.1 ether on every card printed. It’s implemented as a smart contract, whose verified source can be seen here, which has several useful features:

  • You can verify that a deposit was paid for your card by providing its address to the contract (or use our verification tool), meaning you know we put down a deposit for every card we print.
  • Once deposited, funds can’t be withdrawn by us until the guarantee expires, a year later.
  • The auditor account can pay out claims from the guarantee account. If a payout is made, that fact is recorded in the contract so you can see that for yourself.
  • Any claims are paid from the oldest deposits - meaning that we can’t withdraw funds until the account has been made whole again.

Currently, we hold the position of both owner and auditor; as grows and matures, we expect to find trustworthy individuals to appoint as independent auditors.

We think that the contract provides a good way to reduce the level of trust you have to place in us, both by providing compensation, and providing concrete proof of our good behaviour, and we hope you agree.

Big changes at


If you visited us in our first week or two, you might have noticed things have changed a bit around here. The response to our initial launch was overwhelmingly positive, so we’ve been working to improve things further and turn this from a quick test run into a real, lasting project. For this we owe huge thanks to all the people who placed orders, spread the word, and generally made the launch such an astounding success - thank you all!

The first, most obvious, but least important change is that the site (hopefully) no longer looks like it was thrown together in half an hour in Gandi’s site editor. We’re not graphic designers but we’re doing our best to make everything attractive and easy to use. The site’s now hosted on Github Pages - you can see the source here - and is set up with SSL, too.

The second big bit of news is that we’re now using to accept payment for Ether Cards. That means we can take payment in Fiat (GBP), as well as ETH, ETC, and BTC.

The next big bit of news is that we’ve bought our own card printer!

This will enable us to order blanks - cards with everything but the keypairs printed on them - and do the final high-security step of printing the keypairs entirely inhouse, substantially reducing the number of individuals who have to handle this important information. Look for a post detailing how we handle key material in coming days.

Next, we’ve implemented a smart contract that holds the guarantee money, which can be used to pay compensation in the event of a compromise of private key information. We’re confident that won’t happen, but we don’t expect you to trust us - so we’re doing everything we can to minimize the need to. The contract also allows you to verify that your Ether Card had a deposit paid, so you can be sure we’re not printing cards without putting down the security deposit on them. For lots more details on how that works, see this post, and you can verify your own card here.

Finally, we’re looking into ways to improve the cards themselves. There’s two main aspects we’re looking at. First, replacing the QR code private keys with mnemonics similar to those used by Bitcoin, allowing you to more easily enter a private key on a computer when the time comes to sweep your funds. Second, we’re investigating password protected private keys, again based on a Bitcoin standard, which would allow you to order a custom Ether Card whose private key is protected by a password, which you never have to disclose to us, making it impossible anyone but yourself to determine the private key.

We’re also planning to expand the range of designs we offer, including some for the coming holiday season. If you’re a graphic designer, and are interested in some work, please get in touch.