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Cyclebit Tangem Card

🔍 Last analysed 3rd November 2022 . Bad Interface

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Try out searching for "lost bitcoins", "stole my money" or "scammers" together with the wallet's name, even if you think the wallet is generally trustworthy. For all the bigger wallets you will find accusations. Make sure you understand why they were made and if you are comfortable with the provider's reaction.

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The Analysis 

Product Description

Cycle Card is a ‘cold storage’ wallet with high-grade hardware protection, developed by Tangem. Non-retrievable private keys prohibit the replication of the card and assets stored on it

Each Cycle Card is bound to a one-off depersonalized wallet address on the blockchain without any personal accounts or private servers. Backed by 100% uptime and an unblockable P2P network of all blockchain nodes.

It can be paired with the Cycle Wallet which is available in Android and iOS

Analysis

This is a Tangem branded offering which can be used by retailers together with Cyclebit’s point of sale solution. Just like other Tangem products listed above, the card does not have a display or an interface.

(dg)

Verdict Explained

The design of the device does not allow to verify what is being signed!

As part of our Methodology, we ask:

Can the user verify and approve transactions on the device?

If the answer is "no", we mark it as "Bad Interface".

These are devices that might generate secure private key material, outside the reach of the provider but that do not have the means to let the user verify transactions on the device itself. This verdict includes screen-less smart cards or USB-dongles.

The wallet lacks either an output device such as a screen, an input device such as touch or physical buttons or both. In consequence, crucial elements of approving transactions is being delegated to other hardware such as a general purpose PC or phone which defeats the purpose of a hardware wallet.

Another consquence of a missing screen is that the user is faced with the dilemma of either not making a backup or having to pass the backup through an insecure device for display or storage.

The software of the device might be perfect but this device cannot be recommended due to this fundamental flaw.

The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.