Professor Zheng Yan
One of Invent With Nokia’s most prolific inventors, Professor Yan is the author of over 280 peer-reviewed articles and two solely authored books. She is currently a Huashan Distinguished Professor at the Xidian University, Xi'an, China and a Finnish Academy Fellow/visiting professor at Aalto University, Finland.
Systems and techniques for controlling access to data are described. Data is delivered to a repository in such a way that access to the data can be controlled, for example, by encrypting the data before delivery. The power to provide a requester with the ability to gain access to the data is divided, so that multiple entities can provide the requester with a portion of the information needed to gain access to the data. The portions of the information may be partial keys that can be assembled into a complete key. The requester can gain access to the data only if it receives all portions of the information needed to gain access to the data, and different criteria may be used to decide whether or not to provide each portion of the information to the requester.