Collaborative design by sharing multiple-level encryption files

Abstract

A design file can grow in size as the complexity of the target object increases. A large design file can reside in a large parallel computing system, such as a cloud computing system, and many designers can work concurrently on the same file. In such a case, it is obvious that we need some kind of protection mechanism allowing each user to access only the area of the file they are permitted to access. We take the encryption approach to ensure the safety of a file, even in the public domain such as on a cloud system, and in this article, we suggest a multi-level encryption scheme allowing each user to access a file only at the level the user has legitimate right to access. Each level of the file is encrypted with a different key, and the keys are shown only to those who have the right access permission. This article describes the necessary file format used to achieve this goal and discusses the file manipulation functions used to handle this new file format.