As mobile and network technologies proliferate, so does society's awareness of the vulnerability of private data within cyberspace. Protecting private information becomes specially important, since researchers estimate that 87% of Americans can be identified by name and address, if their zip code, gender, and birthday are known to intruders. The goal of this proposal will be to develop a new set of verification tools, algorithms, and interfaces that enable secure, effective and unobtrusive management of users' private information.