Invariant abstractions have played a fundamental role in knowledge accumulation and capital deepening in the field of computer science, of which an example in the past 20 years is the resource abstraction in RESTful Web services and cloud computing. An important direction in future computer science research is computing for the masses in a ternary universe of the human society, the cyberspace, and the physical world, whereby the resource-centric paradigm will shift to a user-centric paradigm, enabling personalization of future information products and services. This calls for a new invariant abstraction, i.e., a universal compute account (UCA) for each user to utilize human-cyber-physical resources in a tetherless and seamless way. This paper discusses the basic properties and organization of UCA, and presents a personal information asset algebra as well as a prototype implementation of the corresponding data asset management system. Analysis of experimental examples shows that the UCA and the asset algebra system facilitate data integration and sharing, thus alleviate the current problem that users personal data are scattered and locked in many vendors devices and services.