Microsoft Technology Licensing, LLC

Andrey V Lelikov

Kristjan Eric Hatlelid

Caglar Gunyakti

Nathan Jeffrey Ide

Aaron Payne Goldsmid

Nir Ben Zvi

Matthias Hermann Wollnik

Karan Singh Dhillon

John Richard McDowell

Methods and a tool or instrument for performing the methods of protecting a computer program with a parameter cloud are disclosed. A parameter cloud comprising a plurality of elements may be created. Called functions of a computer program may have defined expected parameter cloud states so that proper behavior of the called function is achieved when the parameter cloud state is the expected parameter cloud state. An expected parameter cloud state may include a selected set of elements of the parameter cloud having assigned values. Static portions of the called functions may depend on a current parameter cloud state, and calling functions may transform the parameter cloud state prior to calling their respective called functions. The methods and instrument may operate on original source code or post-binary targets of the computer program. A fingerprint may be used to identify a specific computer program from a sequence of state transitions.

Software protection through interdependent parameter cloud constrained software execution

A first process operating on a computer comprises code to be executed in connection therewith, where the code includes at least one triggering device. A digital license corresponds to the first process and sets forth terms and conditions for operating the first process. A second process operating on the computer proxy-executes code corresponding to each triggering device of the first process on behalf of such first process. The second process includes a license evaluator for evaluating the license to determine whether the first process is to be operated in accordance with the terms and conditions set forth in such license, and the second process chooses whether to in fact proxy-execute based at least in part on determination of the license evaluator. Thus, the first process is dependent upon the second process for operation thereof.

First computer process and second computer process proxy-executing code on behalf thereof

Sensitive data is stored in a secure buffer, and never in an unencrypted, accessible location at any time. The data is accessed only by low-level processor instructions that load only a portion of the data into processor registers. The portion of data can then be used before the next portion of data is transferred from the secure buffer into the processor registers. In some embodiments, only one portion is available at any time. In other embodiments, a number of portions may be available at one time. However, the entirety of the sensitive data is never present in the clear. Thus, the entirety of the sensitive data will never be available if an adversary gains access to the contents of memory.

Securing sensitive data in memory

A mechanism for redirecting a code execution path in a running process. A one-byte interrupt instruction (e.g., INT 3) is inserted into the code path. The interrupt instruction passes control to a kernel handler, which after executing a replacement function, returns to continue executing the process. The replacement function resides in a memory space that is accessible to the kernel handler. The redirection mechanism may be applied without requiring a reboot of the computing device on which the running process is executing. In addition, the redirection mechanism may be applied without overwriting more than one byte in the original code.

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Redmond, WA, United States of America

Andrey V Lelikov