External storage

Abstract: The present invention is an interactive computer system which may operate on a computer network. Subscribers interact with a fully interactive programthrough the use of input devices and a personal computer or a television. The multiple video/audio datastreams may be received from a broadcast transmission source or may be resident in local or external storage. In response to user inputs, a personalized graphics, video and/or audio presentation is provided to the user either immediately or at a later time. If not presented immediately, the interactive computer system utilizes "trigger points" to determine when to enable multiple multimedia segments during the show. The CPU uses embedded or stored authoring commands for integrating the various multimedia elements. The interactive multimedia computer enables seamless flicker-free switching from one signal to another on the same or different channels.

Abstract: A computer system for processing and committing data comprises a processor, an external storage device such as DASD or tape coupled to the processor, and a working memory such as RAM. An application program updates data in the working memory and then requests that the data be committed, i.e. written to the external storage device. In response, an operating system function determines which data or blocks have been changed and supplies to an I/O service an identification of the changed data or blocks to cause the I/O service to write the changed data or blocks to the external storage device. Thus, the application program is not burdened with the management of the I/O. The operating system permits the program to continue with other processing while the data is being written from the working memory to the external storage device. As a result, the program need not wait while the data is written to the external storage. Also, because little time is required of the program in the commit process, the program can frequently request commits. With frequent commits, there is less chance that the data will have been written to back-up memory or back-up storage (due to an overload of the working memory) between commits, and as a result, time will not be required to read the data from the back-up memory or storage into the working memory en route to the application program's external storage. Also, the frequent commits reduce the chance of overloading the I/O subsystem.

Abstract: We describe schemes for the oblivious RAM simulation problem with a small logarithmic or polylogarithmic amortized increase in access times, with a very high probability of success, while keeping the external storage to be of size O(n).

Abstract: A scrambled data transmission is descrambled by communicating encrypted program information and authentication information between an external storage device and block buffers of a secure circuit. The program information is communicated in block chains to reduce the overhead of the authentication information. The program information is communicated a block at a time, or even a chain at a time, and stored temporarily in block buffers and a cache, then provided to a CPU to be processed. The blocks may be stored in the external storage device according to a scrambled address signal, and the bytes, blocks, and chains may be further randomly re-ordered and communicated to the block buffers non-sequentially to obfuscate the processing sequence of the program information. Program information may be also be communicated from the secure circuit to the external memory. The program information need not be encrypted but only authenticated for security.