Appendix A: Design principles of the OWF software engine It’s too early to define any specifics about the OWF wallet stack. Over time, the OWF will wrestle with these issues and clearly define For example, the OWF software engine likely won’t include any what the foundation provides and what wallet developers must branding, interfaces, or smart contracts. Those will remain up to build. each developer to create. The OWF founders do agree on something important: the design But what about agents? Functional modules? Plug-ins? philosophy that will guide all our discussions. This table shows the key design principles the project will follow, along with the benefits of each one. PRINCIPLE DESCRIPTION BENEFIT Portable Users can freely move assets, credentials, documents, No user assets or identities are controlled or locked in by and any other data between any wallets based on the any vendor OWF engine Highly secure User assets, credentials, and all other data are protected Users trust the OWF engine against malware and hackers, and updated quickly as criminals come up with new tactics Privacy-preserving User’s digital identities are only selectively Users remain in control of their personal data and digital disclosed as needed identities Standards-based OWF supports all relevant standards for all layers of the Wallet developers do not need to rewrite software over wallet stack and over as standards evolve Interoperable Any wallets based on the OWF engine can quickly and Users don’t need a different wallet for each credential, securely exchange data function, or merchant Multi-function Developers create proprietary plug-ins and interfaces on Developers add unique branding, functions, and top of the OWF engine interfaces to differentiate their wallets WHY THE WORLD NEEDS AN OPEN SOURCE DIGITAL WALLET RIGHT NOW 12