Before signing: what to check in a Bitcoin transaction

An offline signature protects the moment of authorisation. Learn to review the destination, amount and fees before approving a PSBT.

Cuvex · 2026-10-30

Signing is a decision

A PSBT brings together information about a Bitcoin transaction so that a compatible signer can review and authorise it. Preparing the transaction and signing it are separate steps. An offline device helps keep the signing operation separate from the connected environment, but it cannot know by itself whether the recipient is the person you want to pay.

Before approving, check the destination address through a reliable channel, the amount and the fee. Cross-check on the device the details that the model and firmware version allow you to review. If something does not match or you do not understand what is displayed, stop. A confirmed Bitcoin payment has no universal undo button.

Know your model's workflow

Cuvex BIT and Cuvex Original support Bitcoin PSBT signing, with different transfer workflows. BIT transfers data via USB-C and has no NFC or Bluetooth. Original uses NFC cards in its workflow; its USB-C is for power and its Bluetooth is for the firmware update process through the bootloader. Do not interchange instructions between models without checking the relevant guide.

Separating the signing process reduces exposure, but does not eliminate human error, compromised firmware, physical tampering or problems with the connected device. Verify the equipment's origin and use official instructions and firmware.

Viewing is not signing

A watch-only wallet lets you observe addresses and transactions without storing the private keys needed to sign. This is useful for reviewing activity, but access to a wallet's public data may also reveal information about your activity to the services used. Coin Control helps select the outputs to spend; it does not make a transaction anonymous by itself.

Likewise, accepting a payment request in a chat is not the same as signing a transaction. Keep the conversation, payment preparation and final authorisation separate.

Take the next step with a small test

Watch the device video tutorials and practise the workflow with a manageable amount before moving significant funds. Review the comparison between BIT and Original to choose the connection and media that suit your use. Never enter your seed, private keys or passwords in the store, the support chat or a web form.