Abstract: The invention provides techniques to implement unique identifier for an integrated chip and how this ID can be employed to enhance the security of content in personal video recorder type systems. The storage device can be a hard disk, a removable storage medium or any other type of storage medium. An integrated circuit (IC) within the personal video recorder stores a unique identifier that is used in for encryption and decryption of data stored on the storage device. Several embodiments are disclosed herein that maintain the secrecy of the unique ID such that it is not easily accessible thereby defeating the security scheme.

Abstract: The present invention addresses the problem of describing an arbitrary object (up to user-defined limits) given a set of triangles with vertex normals describing the object. A novel method of successively merging traingles into larger and larger patches to compute a set of "as-few-as-possible" Bezier patches is presented. This method is not only applicable to arbitrary objects, but also aims at producing as few patches as possible depending on the geometry of the input object. Also presented are methods to enforce C.sup.0 - and C.sup.1 -continuity between a pair of patches B.sub.L (s,t) and B.sub.R (s,t), placed arbitrarily. The methods perturb the appropnate control points to achieve geometric continuities. For C.sup.0 -continuity the area of the hole between the patches is minimized by formulating the area as a series of linear programs, where the continuity has to be enforced across the adjacent boundary curves B.sub.L (1,t) and B.sub.R (0,t). Similarly, to enforce C.sup.