# Security and Usability The [two-party protocol](/keyfusion/key-concepts-and-techniques.md) is designed for simplicity and security. The system has two roles: **Users** (who are the signers) and the wallet **Provider** (who assist in computations). Users always control their assets, and no transaction can happen without them. The OPZ app introduces a wide range of backup options, prioritizing self-custody and secure key recovery. However, we anticipate that this will never be used in the vast majority of cases. To further simplify the user experience, OPZ also offers an extremely simple restore-from-backup method. ### **Backup Methods** * Backup Recovery Key using 2FA * Encrypted MPC Key stored in any NFC device * iCloud/Google Cloud * Manual backup Methods *** ## **Ensuring Full Control to Owners:** A key feature of the wallet is that at any point in time, the Owner can recover the full private key. This is achieved through an advanced settings mode. {% content-ref url="/pages/INl8vje2l70Efm1RwOYI" %} [Advanced Settings](/opz-app/advanced-settings.md) {% endcontent-ref %} Once enabled, navigate to "App Preferences" and click on "Backup your private Key." Follow the steps by entering your password and 2FA details to complete the backup process. {% hint style="warning" %} Backing up a full private key poses security risks! {% code overflow="wrap" %} ```json While we provide the option to back up your full private key, we strongly advise against this due to the security risks associated. Your private key gives full control to your wallet; if lost or stolen, it could lead to losing your digital assets. ``` {% endcode %} {% endhint %} --- # 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://whitepaper.opz.io/keyfusion/security-and-usability.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.