Abstract: A data security system employing an automatic time-stamping mechanism for stamping a current time code in a data storage area or register associated with each storage section of a memory or an auxiliary storage device, such that each data read or write in a memory storage section updates the time code device. For every storage section of a memory, there is a time stamp storage element associated with it. Similarly, there is a time stamp storage element associated with every data channel. Whenever a storage section of memory is read from or written into the time stamp in the form of a unique binary number from a clock, indicating the current time of day and the date, is inserted into the time stamp storage element associated with that memory storage section. Examination of the contents of each time stamp storage element enables determination of whe the last read or write in a storage section occurred.

Abstract: An operating system authenticator for determining if an operating system being loaded in a computer is valid. A user's identification code or secret key which is unique to the operating system, and a verifier value which is a predetermined function of a valid operating system and the identification code are respectively stored. A hash function, which is a function of the operating system being loaded and the identification code, is generated by the authenticator. After the operating system is loaded, the hash function is used as an authenticating value and compared with the verifier value for determining the authenticity of the loaded operating system.