Frequently asked questions


General

What platforms to you support?
We support both Android and iOS. More platforms are planned for the future.

Can the iOS wallet communicate with an Android device set up as offline storage and vice versa?
Yes. Either using BLE or using QR data transfer.

Will you support other currencies?
If you want us to support a specific coin, please contact us at info@coinid.org

How are fees calculated?
We use Bitcoin Core's estimate fee RPC call.

When will you release a desktop version of the wallet?
TBA.

Do you support Bech32 addresses?
Yes we support generating and sending to Bech32 addresses.


Requirements

General Requirements?

  • iOS 9.3 or higher. Android 4 or higher.

  • Camera or BLE support is required for cold storage.


How to

How do I setup a cold wallet?
It's easy, follow our guide!

How do I setup a hot wallet?
It's easy, follow our guide!


Security

Do you use a secure random generator when generating the Mnemonic?
Yes, for iOS we are using SecRandomCopyBytes, and for Android we are using java.security.SecureRandom.

How does the two phones communicate with each other? How does the offline device share the signed information with the online phone?

  1. The wallet sends the raw unsigned transaction data to the offline COINiD Vault.

  2. When the vault have received the data the transaction is shown for verification. The user then signs the transaction with their pin or TouchID.

  3. The signed transaction is then sent back to the wallet and the wallet then publishes it to the blockchain.

Important to note, nothing sensitive is sent between the devices. Only the same information that is later published on the blockchain. We are using BLE or QR data transfer for offline communications.

How can I make sure that the transaction I sign in my COINiD Vault is correct in case that my online device has been compromised?
You should always verify that the address and amounts presented in the Vault are the same as in the Wallet.

Is it possible to validate that the generated receive address is correct?
Yes, open the receive dialog. Press the more options dots and select Validate Address. COINiD Vault will open, and after you verify with the pin, it will display the correct derived address. Make sure that it matches the one presented on the Wallet.

Is the data sent over BLE between Wallet and Vault encrypted?
Yes, we encrypt it with our secret key and the randomly generated connection code.

How are transaction history validated?
We use multiple external servers for decentralized validation.

How is my mnemonic stored?
It is encrypted and kept in the iOS Keychain or Android Keystore (Android 6.0+). For Android 4 and 5 Facebook Conceal is used to encrypt the stored data.

Do my private key ever leave my device?
No, your private key never leaves your device. You are in full control of your private key.

Do you provide deterministic builds?
Since we need to distribute the app via the App Store that is not possible. The source is however available on our Github so that anyone can review and compile it.

 

Can't find your answer?

Send us a message and we’ll get back to you as soon as we can.
info@coinid.org