Topic: Firmcoins - A new kind of Bitcoin physical bill ready for off-line transactions (Read 11316 times)

I certainly hope it does make a comeback, it sounds awesome!  These are the type of innovations needed to bring BTC to the masses.

After some firmcoin prototypes were created, a new company was built to create firmcoins en masse at low costs. The new design was called Digibill and the company behind it was called Doosra.

Sadly, due to different conflicting visions on how the project should grow, the founding team split and the project was abandoned.

It will someday make a comeback, because it's super cool.
The most similar project is Opendime (opendime.com).

Did this progress any further. Am keen to find out more about what happened to the project.

howsit going with ja firmcoins project? We'd love to integrate these into my forthcoming media/not for profit projects!   x10 many thanks!

Firmcoins are not completely hack-proof nor any device I know of. With enough money it's possible to crack anything.

Was is important is that Firmcoins are designed so that cracking a single Firmcoin does not give the attacker a significant advantage for cracking the next one.  We've put a lot attention to protect the Firmcoin from software bugs, which could be exploited from the outside world without physically compromising the device.

There is no global key, nor shared symmetric secret that you can extract from a Firmcoin, to use in another Firmcoin. Almost everything that's inside the Firmcoin, you can extract by just asking the device for it.

So if a Firmcoin holds 1 BTC, and cracking a Firmcoin costs 100 BTC, then there is no incentive on cracking it for money. I even expect that a university will crack one some day, and that won't affect the security of Firmcoins as a means to make low to medium valued payments (e.g. less or equal to 100 USD per Firmcoin). The same is true for bank notes (and that's why there are no 1M USD banknotes)

If you want to pay more, you're probably in a a context where you're online and you can just make a normal Bitcoin transaction.

The key property of a Firmcoin is not tamper-proof, but tamper-evidence.

I know you guys are going to extreme lengths to keep people from 'cracking' these. I do apologize in advance, but hackers and crackers WILL break into and or intercept information from the device. The length of how far they can go, I am not sure. It is INEVITABLE though. I think if people can crack software and hardware that took multi-million and billion dollar companies years to create, then someone with enough time and knowledge or exploration factor will be able to do something you're not supposed to with a firmcoin. I still want one

HOW TO ORDER??? /When??

Add still another layer of physical security.  It's a measure to deter counterfeiting, but REALLY it does not buy much additional security as I suppose that holograms can be reverse-engineered and cracked.

What is the purpose of the hologram sticker?

All info is in the FAQ (http://firmcoin.com/?page_id=29)

The idea is that the device is tamper-evident, and the private key is chosen by the Firmcoin and stored in tamper-proof memory.
If someone has violated the security of the device, the payee will know.
 

How to order?

so how do you flash check the chip to verify that it is not been corrupted or 2x spent~~~many thanks

Thanks!


The process involves using both a hardware random generator and a firmware random pool. But most important, the process is a two-party computation where the hardware cannot force a certain key-pair, not generate key-pairs with any probability distribution other than uniform random.
Regarding saving the keys somewhere, there is no problem with saving these keys. Whenever you decide to extract the funds from a Firmcoin, you should also transfer the funds to another Bitcoin address.
Nevertheless, the Firmcoin will wipe the keys from memory and it can prove (yes it can) that the keys have been erased.
The way it is proved is by a method I created that is called "practical compressibility".  Basically the device will fill its memory with some incompressible data and then send you a hash of this data in reverse order, proving that there is no free memory left that can hold a private key.


Yes, I've already discussed this setting somewhere in the bitcointalk forum (here https://bitcointalksearch.org/topic/m.2463058)


First you don't create the key: the Firmcoin creates the key.

To fund the Firmcoin you either give it a block-chain-branch which proves that the funds were transferred to the Firmcoin or you get a certificate from one or more Certificate "authorities" that prove that the address is funded. If many people trust you, you can become your own CA for Firmcoin funds.
Both methods can even coexist, because the Firmcoin remembers the certifications it has.

So why didn't you write this line BEFORE the questions so didn't have to answered all your questions!! :-)


I owe you an more technical answer to this question, but there are many usage factors we still don't know.
The product durability is affected by both physical and usage patterns (that affects the number of FLASH/EPROM write cycles).
The physical properties are very good, since there are no holes, nor connectors and all the prints are inside the package.

My rough estimation is that a Firmcoin can last more than 10 years funded and more than 50 years if the Firmcoin is empty or you don't care if the funds are lost afterwards. We could add the Firmcoin a procedure to "refresh" the memory, so if you execute this function every 5 years, you could have the same funds stored for 50 years. But I'm almost sure that the Bitcoin protocol will change in the following 50 years so you will probably need to do something with your wallet and coins (probably change the signing scheme) before the Firmcoin will wear out.
If the Firmcoin is reloaded every day, it will reach the maximum write-cycles in 270 years.


Best regards,
 Sergio.

Excellent.

I've pretty much had thoughts about this exact product, only lacking the technical know-how to actually create it.

First thought, how secure is the key generation in this? I'm thinking partly about the generation algorithm (deterministic? random?), but also on what kind of guarantees customers have that you aren't saving all your keys somewhere.

Second thought, you could make these cards even more trust-free by using 2-of-2 transactions, where one key is generated by the card and the other is generated by the customer's own device. Thus, when I recieve a card I generate a key by myself and give it to the card and therefore know that you can't steal my funds. If I give the card to someone else as payment he knows I can't steal the funds since I don't have access to the key generated by the card.

Is there any clever protection against fooling the card making it think it has funds when it doesn't? The card would have to rely on data from your own device, so how come you can't just create a new key and tell the card it's funded?

Edit: All the bolded was answered to satisfaction by simply reading your FAQ.  

Only one of my questions remains then. What is the life expectancy of these cards and how durable are they?

They are similar in many things, specially in tamper-proof measures.

Yes but a Smartcard will sign anything you ask it for, for example, a transaction, so it will happily loose its funds.
A Fiirmcoin will also sign anything you want, but it will immediately enter the "empty" state.
A Firmcoin will sign special messages that cannot be transactions, to prove the possession of the private key.

Yes.

Sergio.

We have two models: one (the cheapest) has fixed denominations. The other has a display that shows the Firmcoin balance.

I assume that firm coins have a private key (of the "firm") embedded in them.  The card would first prove it is a valid firmcoin card.

From your Why? page, I found
I am at a loss to figure out what makes Firmcoins special compared to smart cards (whether they are NFC enabled or not).
If a private key is stored in a smart card, the card can read a message and return a signature, thus proving it holds the key to a given address.
Also, smart card prototypes with input buttons have been displayed by smart card manufacturers, right ?

That is pretty cool. 

It says 1BTC on it, so does that mean the intention is for them to be fixed denominations?

Congratulations for the idea, Sergio! I hope to have the possibility of buying those lovely Gizmos...

Best regards.

It's true that hackers are always finding new ways to crack crypto, but since we've hired hackers ourselves, and we follow the best security practices, and we follow closely the security research, we think we will be well protected.

Now, if you see the video, they are using two type of attacks:

1. An active attack to measure the power consumption of the device to extract some "master key".

Firmcoin do not have any master key, so there is nothing to extract in one Firmcoin that let you crack another FirmCoin. If you physically break your Firmcoin, nobody will accept it as payment.

2. A passive attack technique "Side Channel Attack" to compromise some information sent by RF (without breaking the device). This kind of attacks are based on the fact that the device performs cryptographic operations using private keys. The attacks presented require repeating the same operation over and over.

If you have a Firmcoin will only send its private key after entering the "no funds" state, so there no advantage on capturing the RF signals.

You could try to attack the function that a Firmcoin can execute a private-key proof of knowledge operation. This would be the weakest point of the Firmcoin security. Currently, to prevent side-channel attacks, we four protective measures:

A. We use a side-channel protected modular exponentiation algorithm
B. We use randomization techniques to make difficult to predict where an operation is taking place.
C. We limit the frequency of proofs the Firmcoin can execute, currently at 1 every 5 seconds (after the power is applied, you must wait 5 seconds before requesting such a proof).
D. We use an industry standard tamper-proof micro-controller, made by a company with more than 10 years of experience in smart cards.

Nevertheless we might remove the private-key proof of knowledge feature if we are not totally satisfied with our power analysis tests we'll perform on the final device we'll use for mass production.

Best regards, Sergio.