Bitcoin Forum

Today, Mycelium has announced the launch of an Indiegogo project for its Mycelium Entropy device (https://www.indiegogo.com/projects/mycelium-entropy). Mycelium Entropy is the newest addition to the Mycelium Bitcoin Wallet ecosystem, first announced at the Bitcoin2014 Conference in Amsterdam, and demonstrated at the Central Europe Bitcoin Expo in Vienna, as well as the recent Bitcoin in the Beltway conference in Washington DC. The project fundraiser was initially delayed when Kickstarter decided to deny it on the grounds that "Kickstarter's guidelines do not allow for offering money processing services." Attempts to explain that a hardware random number generator is not in any way a "money processing service" has failed, but the Mycelium team was not deterred, and we found a new place to host the fundraiser.

Mycelium Entropy is a small, simple USB device that is designed specifically to generate paper wallets. All you do is plug it into a printer's USB port, and the device uses specialized hardware to create a random number with 256-bits of entropy. It then uses that number to generate a paper wallet with public and private keys, which your printer sees as a JPG photo that it can print directly from the device. This is currently the most secure way to create paper wallets, since the keys are never exposed to the web, use true high level entropy, and only exist on paper. For extra security, Mycelium Entropy can also create M-of-N split keys, where the private key is split up in such a way that you need two out of three parts to spend from an address. In this way, if one of your paper backups is lost or stolen, the thief still can't steal your coins, and you can still access them using the remaining 2 paper backups. Since the Mycelium Bitcoin Wallet has full support for spending from paper wallets, using Mycelium Entropy in combination with the Mycelium Bitcoin Wallet can be a very safe and easy way to store and protect your savings. Think of it as being able to create your own bank deposit certificates that you can keep in a safe, while keeping only a bit of spending cash on your Android wallet. With this combination, the idea of "Be Your Own Bank" comes much closer to reality, and becomes much easier as well.

At this stage, the devices are fully functional, and need just a few minor software tweaks, such as fixing issues of incompatibility between US and European sized paper standards causing the headings on the paper wallet image to be cut off. Mostly minor things that will be resolved by the time we are ready to launch. Although the device hardware is open source, we need to raise money to be able to order them in sufficient enough quantities to make them cheaper for everyone, since mass production is much cheaper than ordering them one at a time. Also, about $1,500 of the money raised will go towards testing and compliance for these types of devices, like CE marks, FCC part 15 approvals, etc. While the devices are being developed, we will spend time testing printers and putting together a list of recommended printers to use with these, just to make sure that yours can handle this, or if it can't, to help you find the cheapest (and most secure) option you can get.

You can read many more details, and see examples, on our Indiegogo page (https://www.indiegogo.com/projects/mycelium-entropy).

Very interesting project, and great price point. I'll be contributing.

This is very useful. +1

Is there an option to contribute using Bitcoin?

There's only PP and CC displayed as payment options on indiegogo.

Sadly, indiegogo offers no other payment options.
The devices will be available for bitcoin once the funding project is done and regular selling starts, though.

I love this project. Do you have plans to add support for M-of-N split keys in mycelium ? I mean a feature to scan the paper shares.

Absolutely. This feature was demoed at Bitcoin2014 in Amsterdam and 2 weeks later in Vienna.
We have it on a dev branch for now. There is work on turning it into a BIP, and we hope that becomes a reality before we ship the first devices. (Look for bipss on the dev mailinglist)

The current deaft supports M of N with any of those combinations: 1 <= M <= N <= 255

Thanks for your answer. It is really good news, I am such a fan of paper wallets.

*bump* We're about a third of the way there, and we still need your help. Please let others who don't use Reddit or bitcointalk know about this.

How secure would it be to use these at a print shop or other public printer?

General answer: Not at all secure. You never know what software or physical modifications have been applied to those printers, and if anyone was aiming to get private keys printed on them, he would probably find a way to do so, with access to the printers. How likely this scenario is, on the other hand, is another question. But the point is, even if you trust the printshop not to steal your keys on purpose, those printers there have probably fancy abilities and configurations, like maintaining a history of printed documents. And printing private keys in public is a bad idea on its own, if somebody can see, film, foto... your key, i would not use it anymore. Video surveillance could film you printing it, and the security guy or whoever has access can just take your money.

So, better print keys at home, on an offline printer, with no persistent document history.

Agree.
If you don't have a printer that allows you print JPGs from directly from a USB stick then it is possible to insert it into your computer, and print the JPG off the Mycelium Entropy to your printer.
BUT: Then you have to trust your computer not to be compromised!
The chain is no stronger than its weakest link.

Of course "with NO persistent document history" is what i wanted to say.
The printer should not store printed docs on a harddrive.

We are at 35%. Help us get this project rolling: https://www.indiegogo.com/projects/mycelium-entropy/x/8022340

Crosspost from Reddit:

Mycelium has been running the Indiegogo fundraiser (https://www.indiegogo.com/projects/mycelium-entropy) for the Entropy device for a few weeks now, and we were really trying to avoid something like preorders (this was more of a fundraiser to see if there is enough market demand), and using BTC (due to issues others have had where the price of BTC skyrocketed while devices were delayed).

However, we have received tons of requests from people wanting to support us using bitcoin, so we gave in and added bitcoin links to our Indiegogo site. I have also included them here directly for convenience:

* $15 - Get a Mycelium t-shirt (https://bitpay.com/cart/add?itemId=DScrJ8G8nPcmtvTLRAg4o8)
* $40 - Get a Mycelium Entropy device (https://bitpay.com/cart/add?itemId=L9DSjE61eeiHjkQmKbRTnh)
* $50 - Get a Mycelium Entropy device, and a t-shirt (https://bitpay.com/cart/add?itemId=HYzcV4ZiBvepqqTHmFUs3z)

We were overwhelmed by the success of our Indiegogo campaign. We set modest goals, to be sure to reach them and start producing, but we still need help and support to get these devices made. We will absolutely make sure that this project succeeds, and are even willing to use our own personal funds to get this project done, but anything extra we can get will help us a lot. We are still on target to start shipping by October. Since Indiegogo sends you the money as soon as you hit the goal, instead of at the end of the campaign (like Kickstarter), we have already transferred the money to our European bank account, and are in the process of negotiating the manufacturing order.

In other Mycelium news:

Mycelium will be at the Cryptolina (http://www.cryptolina.com/) conference in Raleigh, NC this weekend, August 15-16th, where I will be demonstrating our Mycelium Entropy device live, and **showing off the new BIP32/HD wallet (https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki) feature in our Mycelium Wallet.** For those who don't know, this will allow you to back up all your bitcoin addresses using only one key (as opposed to making a separate backup for each address), and will make the wallet use a different change address for every transaction, greatly improving security and anonymity. This should also make managing addresses easier, and will allow us to implement CoinJoin for greatly improved anonymity (what DarkWallet (https://www.darkwallet.is/) uses) and make implementing the BIP70 Merchant Payment Protocol (https://github.com/bitcoin/bips/blob/master/bip-0070.mediawiki) possible (which will make paying for things much easier, resolve some issues with who pays the fees, and help make 0-conf transactions more secure). We are getting really close to finishing it, and I for one am very excited.

If you don't reach your funding goal we can try to help you out over at BitcoinStarter.com (http://www.bitcoinstarter.com)!

I love what you all are doing.

Thanks.
Your website does not render on my device, and the video seems no longer available.

The selling point here involves owning a printer with a USB port on the front that one can print from. The cheapest printer I could find on Amazon that definitively had a USB port it could read from was the Epson WorkForce WF-2540, for $79. From my brief search, it seems like printer manufacturers aren't so often including these USB ports, and are more often including a combination of memory card, WiFi, Bluetooth, NFC, or cloud printing features. Does anyone know of other budget level printer models that actually have this USB thumb drive reading capability?

you should be safe using someone else's printer but if you need your own printer you might need to do a bit more research as the printer you cite seems to have that USB port for transferring files or saving a scan rather than for printing from direct to USB.

https://files.support.epson.com/pdf/wf2540/wf2540ug.pdf




List of Printers Tested So Far

Brother HL-4150CDN Color Laser - OK
Brother MFC-J875DW Wireless All-In-One - resets printer when trying to print
Brother MFC-8710DW All-in-One Laser - OK
Brother MFC-9970CDW Color All-in-One Laser - OK

Most Canon printers do not have USB ports.
Canon i560 - does not work
Canon imageCLASS MF8280CW Color Laser - OK
Canon Selphy CP910 - comes out plain white on multiple sheets
Canon PIXMA-MG6250 - OK

Epson XP-610 - OK
Epson XP-810 - OK
Epson XP-850 - OK
Epson WF-2540 - No way to print photos from USB
Epson WF-3520 All-in-One - OK
Epson WF-3540 All-in-One - OK
Epson WP-4540 - No way to print photos from USB
Epson WF-7510 Wide-format All-in-One - OK

HP Envy 120 Wireless - OK
HP LaserJet Pro 200 Color - OK
HP LaserJet Pro MFP M476dw - OK
HP Officejet 6700 Premium - OK
HP Officejet Pro 8600 Plus - OK
HP Officejet Pro 8610 - OK
HP Officejet Pro 8630 - OK
HP Photosmart 7520 - OK


So it looks like the cheapest option is
HP LaserJet Pro 200 M251nw Laser Printer  for 156
http://www.amazon.com/gp/product/B0092VVI3Q/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=A1VSW57XH453U1

Thanks for the info on the instruction manual. Btw, the Epson XP-610 looks to be cheaper, at around $89. I haven't price checked this entire list, so maybe there's an even cheaper one on there?

I think you found the cheapest one. Personally, I would spend a bit more and get the laserjet because inkjets are very expensive per printed page for ink.

Damn, too bad the selphy does not work, it would be a perfect match imo..
Btw. why does it not work with some printers? As far as I understood it generates a jpg picture with the paper wallet info, weird that it cannot be printed on some devices.

Any Entropy news? Are we still on schedule for October / November delivery?

They say it will probably ship this next week --

https://twitter.com/MyceliumCom


Mycelium.com @MyceliumCom  ·  Oct 15

Still no change in expected shipping time for Entropy (by the end of the month), but we'll have a more concrete estimate early next week

I was hoping to be able to give some updates today, but we didn't hear back from one of our manufacturers, so hopefully I'll have an update Monday..

Rassah, thanks for the update here: https://bitcointalk.org/index.php?topic=839479.0

Btw, can anyone confirm for me if the HP Photosmart 8450 is compatible? My folks have that printer model, so I'd like to get them an Entropy if it will work!

Is there an easy way to test for this? Like, put a jpg on a thumb drive and see if the printer detects it?

Yes, that's how you would test it. Plug a USB stick with a jpeg on it into the port, and see if there's some way to print it.

I read through the printer manual, and although it supports printing photos without a computer, it doesn't say if it can do that from the USB port, or if that is limited to just the memory card slots. I asked on Amazon, but if you can just do the USB stick with a jpeg photo test on it, that would be quicker. Let me know if that works, and if yes, I'll add it to our list of compatible printers.

I did, in fact, test it this way; I directly printed a jpeg from a thumb drive plugged into it, so you can definitely add it to the list, then! Looks like I'll be ordering one. :)

Awesome. Thanks!

Hey guys,

I got my Entropy today...

...well... i don't want to be a "spielverderber" but build quality really isn't there.

There is a small gap between transparent and black parts, the button is squeaking whenever i press it and sometimes it does not go back... so i have to pull it out manually with my nails...

After such a long wait... I have to say i am a bit disappointed.

Device itself works fine, though.

Question: can i take the casing off and use it without? Does this change entropy generator in any way?

I received mine.

https://mycelium.com/assets/entropy/me.html