The security architecture of UKey hardware wallet is based on strict physical isolation principles. Its core strategy is through the built-in security chip (Secure Element, SE), Completely isolate the user's core cryptographic asset credentials (private keys) from any external environment (thermal environment) with network connectivity properties.
The following is the standard workflow and underlying security mechanism description of UKey hardware devices:
1. Transaction signature interaction standard process
When interacting on the chain, UKey hardware devices and software clients have a clear division of labor. The hardware is only responsible for signatures, and the software is responsible for network communication. The complete process is as follows:
Construct and issue requests: When a user initiates an on-chain transaction through UKey software client (such as mobile App or browser extension), The client is responsible for constructing the original transaction data package (including the number of tokens, target address, smart contract parameters, etc.) and sending it to the connected hardware device as a signature request.
Local analysis and physical confirmation: The UKey hardware device receives the binary raw message from the software side and completes independent parsing inside the device. The parsed key transaction information will be displayed on the hardware screen. Users are required to perform manual confirmation through physical buttons or hardware touch screens.
Chip-level offline signature: If and only after obtaining the user's physical authorization, UKey's built-in security chip (SE) will call the corresponding private key derived from the mnemonic phrase in its completely enclosed micro-isolation area to perform an encrypted digital signature on the transaction.
Signature data return: After the signature calculation is completed, the security chip only outputs the signed transaction string, and the hardware device sends it back to the external software client.
Transaction broadcast on chain: The software client receives and assembles the complete signed transaction message, and then broadcasts it to the target blockchain network, waiting for verification by network nodes and packaging by miners.
2. Description of core security features
Private key boundary isolation: UKey's hardware architecture design ensures that the private key is strictly encapsulated inside the security chip during the entire life cycle (generation, storage, and call operation) and will not leave the security boundary in any form at any stage.
Command level permission circuit breaker: The system firmware for UKey devices removes at the underlying code level any command interface for reading or exporting private keys. This architectural design fundamentally eliminates the logical possibility of the private key being maliciously extracted.
Restricted one-way communication: There is only limited one-way data flow interaction between the UKey hardware device and any connected third-party software (including the host's operating system) (receiving data to be signed and outputting signed data). External programs cannot access or penetrate the encrypted storage area of the hardware core without permission, thus ensuring the absolute offline security of digital assets.