OpenDime or Hardware Wallet?

[DaveF]

Satoshi Labs should have done more to inform their customers about the security of their Trezors but the risk is overstated.

Not to bash your opinion, but I think your post really should say "Satoshi Labs should have done SOMETHING to inform their customers about the security of their Trezors"

I think that is what is the more serious issue.

They have known about it for months, but you go and but a new one from them the need for a complex password is STILL not mentioned anyplace obvious it the docs.

That is where the issue is.

Keep safe out there.

-Dave

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[Abiky]

Hasn't happened so far so I doubt we will be seeing 'many' users losing their money due to this. Not a single person has shown up to say they lost anything because someone stole their Trezor and they had no passphrase or too weak a passphrase. I'm sure most people who keep a large amount of money on their Trezor use a secure passphrase anyway.

Satoshi Labs should have done more to inform their customers about the security of their Trezors but the risk is overstated.

Good to know. As long as people use strong passphrases for Trezor devices, nothing can go wrong. It's yet the time where no one has experienced issues with them (like the loss of funds), so the company would have no reason fix the aforementioned vulnerabilities on new devices. But I'm better off using tried-and-tested Ledger devices since the company focuses heavily on security than anything else.

I've been considering other hardware wallet options like the CoolWallet S and the FuzeW Wallet. They have a "credit card" form factor, which means that they easily fit on your everyday wallet. I'm not sure how secure these wallets are, but they're a convenient way to carry crypto with you on the go. The only downside is that they're powered by an internal battery, when that's not the case with the Ledger Nano S or the Nano X. My concern is that once the battery dies, you'll have to dispose the device as it becomes useless. Even if my Ledger Nano S' screen is fading, it'll still be usable without it by using the internal buttons. I'm often looking for durability and security, so I'm wondering how these credit card sized hardware wallets will perform over time.

Anyhow, I'll stick with my Ledger Nano S until it dies completely. The OpenDime could be a great addition to my arsenal in case I want to send Bitcoin to another person in a physical manner. With a cost of only $35 per "stick", I'd say the OpenDime doesn't break the bank.

[malevolent]

My concern is that once the battery dies, you'll have to dispose the device as it becomes useless.

It often takes a long time for a device's battery to completely crap itself out, usually it just loses its capacity, and since these wallets last a long time on a single charge, even losing 80% of the battery's capacity won't make using it too inconvenient.

[DaveF]

So because of this thread I ordered some Tangem cards



Look nice. The RFID is a bit weak IMO. My phone reads a lot of other RFID cards easier then this.
With that being said I do not know if it's something in the app that they use doing something odd with the read that is causing it to ask to scan multiple times.
Other (non crypto) apps reading other cards just tap and it's there.

The app is nice, and I can see this as a nice way to pass someone a known amount of BTC (or ETH since I got one of those cards too) without worry.

Stay safe.

-Dave

[Abiky]

It often takes a long time for a device's battery to completely crap itself out, usually it just loses its capacity, and since these wallets last a long time on a single charge, even losing 80% of the battery's capacity won't make using it too inconvenient.

Thanks. It seems that the battery of the Nano X lasts for a very long time. As long I'm able to use the device for a couple of years, nothing else matters. My Ledger Nano S is dying (screen very dim) so upgrading to the new version would be ideal. A great thing about hardware wallets (especially the ones offered by Ledger) is that they're durable, reliable, and extremely secure to use. They may be expensive than other solutions (paper wallets, bearer instruments like the OpenDime or Tangem Card, software wallets, etc.), but I'd say they're worth every penny.

I've been looking into other hardware wallets for Bitcoin, and I've found one called the "ColdCard" by Coinkite. It looks like a little calculator, yet it seems to do its job well for securing Bitcoin transactions on the go. What I like most about this device is that you can make offline transactions with it. It works on its own (standalone) without the need of a computer or mobile device. The only thing is the price, but if it works as intended, it's a great alternative to the Ledger, Trezor, or other hardware wallets on the market today.

So because of this thread I ordered some Tangem cards

..

Look nice. The RFID is a bit weak IMO. My phone reads a lot of other RFID cards easier then this.
With that being said I do not know if it's something in the app that they use doing something odd with the read that is causing it to ask to scan multiple times.
Other (non crypto) apps reading other cards just tap and it's there.

The app is nice, and I can see this as a nice way to pass someone a known amount of BTC (or ETH since I got one of those cards too) without worry.

Stay safe.

-Dave

The cards looks great. I'd personally buy it as a souvenir or collectible, than using it seriously for crypto payments. The RFID chip may be weak, but at least the phone is able to recognize the card. What I like most about the Tangem Card is its variety of crypto offerings including (but not limited to) Bitcoin, Ethereum, XRP, and more. The OpenDime is only limited to Bitcoin and Litecoin, so the Tangem Card has an advantage here.

I wonder if the Tangem Card's level of security has been put up to the test? I've seen that it's possible to steal information from RFID chips using a RFID scanner. Just like anyone with an RFID scanner is able to steal your credit card information (if it has an RFID chip), the same could be done with the Tangem Card. Unless the card itself has some level of encryption, I don't see it as a viable solution for storing crypto in the long term. It's always recommended to store small amounts of crypto on bearer instruments like the OpenDime or Tangem Card just to be safe. For serious crypto use, hardware wallets are unmatched for now.

[DaveF]

I wonder if the Tangem Card's level of security has been put up to the test? I've seen that it's possible to steal information from RFID chips using a RFID scanner. Just like anyone with an RFID scanner is able to steal your credit card information (if it has an RFID chip), the same could be done with the Tangem Card. Unless the card itself has some level of encryption, I don't see it as a viable solution for storing crypto in the long term. It's always recommended to store small amounts of crypto on bearer instruments like the OpenDime or Tangem Card just to be safe. For serious crypto use, hardware wallets are unmatched for now.

According to the FAQ on Tangem:

What if somebody scans my Card and transfers the funds from it?

Not to worry - nobody will be able to transfer funds from your Card just by scanning it. Although checking the funds takes seconds, transferring them requires you to hold the Card against your phone for 15-30 seconds.

This is a security measure, its duration is configurable and it can be overridden by enabling a PIN-code on the Card (available on demand).

So you can have some protection. The issue I see is that you NEED the Tangem app to unload that card. They disappear in the middle of the night that could be an issue.
You can't even get your private key from the card.
Once again from their FAQ:

How can I backup the private key?
You can neither import the private key into a Tangem Card nor export the private key -- so it’s completely impossible to have a copy. The architecture of each Tangem Card guarantees the chip inside is the only place in the universe where the unique key can ever be located.

But yeah, they are nice looking. Part of why I bought them. Never going to store any crypto on them. It's not 100% not your keys not your coins but it's close.

-Dave

[HCP]

I'm not sure about this part:

Who knows the private key?

Each Tangem Card holds a secure chip that allows you to store and carry digital assets. The private key is generated by and permanently stored within the chip. Nobody has access to it either during or after the manufacturing process. This means that nobody can input, export or make a copy of this key.

So, it appears that the Tangem card cannot be "reset" to regenerate a new key... instead it just arrives "as-is" with a preloaded key? That seems... "problematic".

Still, they look nice

[DaveF]

So, it appears that the Tangem card cannot be "reset" to regenerate a new key... instead it just arrives "as-is" with a preloaded key? That seems... "problematic".

Still, they look nice

In that way they are closer to the opendime then a true hardware wallet.
A better way of thinking about it is a rfid security device that you must have to send bitcoin.
What I did not know (because I did not read they do not hide it) is that you can never get the private key.

Need to sign a message. Nope, not from what I can see in the app.
Another shitfork comes out, can't claim it.
etc.

-Dave

[HCP]

Need to sign a message. Nope, not from what I can see in the app.
Another shitfork comes out, can't claim it.

That's a good point actually... it really is borderline "not your keys", almost to the point of "custodial" except, theoretically, no-one has access to the keys...

Having said that, I guess the point of these cards isn't really to be a long term HODL type device... more a way you can load up some coins and pass them onto someone in a relatively secure (offline) way.

[figmentofmyass]

Need to sign a message. Nope, not from what I can see in the app.
Another shitfork comes out, can't claim it.

That's a good point actually... it really is borderline "not your keys", almost to the point of "custodial" except, theoretically, no-one has access to the keys...

we have to trust their closed source firmware for that to be true, the risk mitigation being that it was audited by a third party company:

The security of Tangem technology is audited by the Kudelski Group, a listed Swiss security company. The report is available here.

that's enough to make me cautious. i would also be slightly worried about physical integrity. i really don't like the idea of having zero back-ups. it has a sweet design though, very slick looking.

[Abiky]

...

So you can have some protection. The issue I see is that you NEED the Tangem app to unload that card. They disappear in the middle of the night that could be an issue.
You can't even get your private key from the card.

...
-Dave

That's a huge concern for those looking to use Tangem cards as a long-term storage for crypto. Since you don't control the private key, you don't truly own the funds. This bearer instrument is only useful for small amounts of crypto or doing quick transactions between peers. If you're looking to store large amounts of crypto, then hardware wallets are your best option.

What I like most about the Tangem cards is their cheap price (and design) compared to other crypto wallets. They make great souvenirs or collectibles that might be worth a ton of money in the future (if they become extremely rare). The Tangem team should've made the app open source so that people who kept their cards for safekeeping, could use them in the future even if the company ceases operations in the long term.

As for the OpenDime, I don't think this will be a concern since data is stored locally on the device without the need to interact with a separate app to read the private key. You could hold your OpenDime for years without worries. The OpenDime could be a true winner in this regard, unless the Tangem team decides to provide an "exit route" to users if they decide to disappear in the middle of the night.

That's a good point actually... it really is borderline "not your keys", almost to the point of "custodial" except, theoretically, no-one has access to the keys...

Having said that, I guess the point of these cards isn't really to be a long term HODL type device... more a way you can load up some coins and pass them onto someone in a relatively secure (offline) way.

Yeah. I wouldn't use Tangem cards for serious long-term storage of crypto, except for performing quick transactions with it. Different types of wallets have their unique purposes in real life. Those looking for a reliable long-term cold storage for their crypto will simply use a paper wallet or a hardware wallet, while those who want to send crypto offline quickly will use an OpenDime or Tangem card.

Nonetheless, hardware wallets are ten times better than the OpenDime but they're relatively expensive. People who cannot afford a hardware wallet could simply use an OpenDime over a software wallet for added security without breaking the bank. At least, we have many options to choose from.