# Device Key The device key is stored safely in the mobile device’s special secure hardware chip: **HSM (Hardware Security Module)**. Examples of HSMs are Apple's Secure Enclave (Apple T2 chip) and Android Keystore. The key is isolated from the mobile OS using a specialized hardware chip to protect it from any security threats, and an app can only request to sign/verify a transaction- meaning that the keys stored in HSM cannot be taken out of the hardware. Therefore, It can be seen as utilizing users’ mobile devices as a cold wallet. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.hyphen.at/concepts/hyphen-multi-sig-account/device-key.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.