Evil Maid Attack

An evil maid attack is a type of attack that involves physically accessing a device or system to gain unauthorized access to sensitive information. The term "evil maid" comes from the idea that a hotel maid could surreptitiously gain access to a user's device while the user is away from their room, leaving the user's data at risk.

In the context of cryptography, an evil maid attack typically involves a hacker physically accessing a computer or device that has been left unattended, in order to install malicious software, replace hardware components, or extract cryptographic keys or other sensitive information. The goal of the attack is typically to gain access to encrypted data or passwords that the user has stored on the device, in the case of wallets this could mean access to the private keys of the wallet to drain funds.

There are a few approaches Cypherock has taken to mitigate the risks of the Evil Maid Attack:

1. Using ultrasonic welding on the X1 Vault: Ultrasonic welding makes it difficult for an attacker to physically compromise the wallet without leaving any traces of damage, thereby alerting the owner of any physical tampering. You can read more about how ultrasonic welding plays a role in X1 Vault hardware security on the dedicated page here.

2. Official firmware is signed by Cypherock's keys at the time: Cypherock has a proprietary provisioning process that ensures the integrity of the X1 Vault. The process helps determine any changes that may have been made to the hardware, or the firmware. The provisioning process is covered in the section talking about how to verify if Cypherock X1 is genuine.

3. The Cypherock X1 avoids a single point of failure with Crypto keys: Cypherock's architecture removes the single point of failure with private keys. This is made possible by utilizing Shamir Secret Sharing which cryptographically splits the private key into 5 parts that are stored individually on the X1 Vault and 4 X1 Cards. Cypherock uses a cryptographic threshold of 2/5 where a user requires any 1 of the X1 Cards and the X1 Vault to make a transaction. Since each of the cryptographic parts can be secured seperately, evil maid attacks become significanlty harder.