Microsoft Technology Licensing, LLC

Microsoft Corportion

Dinarte R Morais

Ling Tony Chen

Boyd Cannon Multerer

Mark Daniel VanAntwerp

Jeffrey Andrews

Michael Courage

Damon V Danieli

Daniel Ron Simon

Josh D Benaloh

Max L Benson

Thomas F Fakes

Sean Christian Wohlgemuth

Jon T Lange

Daniel Caiafa

Eric Neustadter

William Eric Hall

Adam G Poulos

Milind Madhukar Joshi

Paul E Newson

Victor Tan

Sebastian Lange

Darren L Anderson

Scott Norin

Mark D Van Antwerp

Roxana Arama

Andrew R Solomon

Gary A Thompson

Mitsuo Koikawa

William P Champion

Jeffrey A Andrews

Various mechanisms are disclosed for protecting the security of memory in a computing environment. A security layer can have an encryption layer and a hashing layer that can dynamically encrypt and then dynamically hash sensitive information, as it is being loaded to dynamic memory of a computing device. For example, a memory unit that can correspond to a memory page can be processed by the security layer, and header data, code, and protect-worthy data can be secured, while other non-sensitive data can be left alone. Once such information is secured and stored in dynamic memory, it can be accessed at a later time by a processor and unencrypted and hash checked. Then, it can be loaded back onto the dynamic memory, thereby preventing direct memory access attacks.

Tamper resistant memory protection

A computing environment maintains the confidentiality of data stored in system memory. The computing environment has an encryption circuit in communication with a CPU. The system memory is also in communication with the encryption circuit. An address bus having a plurality of address lines forms part of the system and a value of at least one of the address lines determines a key selected from a plurality of keys to use in the encryption circuit to encrypt data being transferred by the CPU to the memory.

System and method for using address bits to affect encryption

Discovery and distribution of game session security information includes receiving a request to generate a new game session from a computing device and maintaining a record of a game session identifier for the new game session and a game session key for the new game session, and making the new game session available for other computing devices to join. A request for information describing one or more of a plurality of game sessions may also be received and responded to with the information describing the one or more game sessions as well as a session key that can be used to communicate with at least one of the one or more other computing devices that are part of the game session.

Discovery and distribution of game session information

A condition on a client that is communicating with a server is determined by issuing a challenge to the client, causing the client to produce a response indicative of the condition. The server compares the response to an expected response to determine if the condition is as expected, and if not, takes appropriate action, such as terminating the connection with the client. The challenge preferably includes parameters and a code segment that causes the client to produce the response by executing the code segment. The code segment could perform a one-way hashing algorithm of a portion of memory indicated in the parameters. The server can thus determine if the client is using a modified basic input output system, modified software, pirated software, or whether other conditions exist on the client. The challenge can be changed to prevent the client from returning a false, predetermined response to the challenge.

Handling failed client responses to server-side challenges

A system comprises a memory and a processor that supports different privilege levels. Only program code executing at a certain privilege level is permitted to map memory and to assign access permission to the mapped memory, such as read-only, writable, and executable. Control code executing on the processor at that privilege level, in response to a request from other code executing at a different privilege level, maps a portion of memory for loading an executable file. After the executable file has been loaded into the mapped memory, the control code then verifies a signature associated with the executable file. If the signature is verified, the control code permits the executable file to be executed by the processor at a privilege level other than the one at which the control code executes. Otherwise, the control code prevents the executable file from being executed on the processor.

System and method for secure execution of program code

A computing environment maintains the integrity of data stored in system memory. The system has an address bus that comprises a plurality of address lines. The value of at least a portion of the address line is determined by a real page number stored in a page table. The system also comprises an encryption circuit that converts data from plaintext to ciphertext as a function of a key value. A circuit derives the key value as a function of at least a portion of the address line that is set by the real page number.

System and method for applying security to memory reads and writes

Machine instructions comprising a bootstrap code are buried within a critical component of an electronic game console where they cannot readily be accessed or modified. A preloader portion in a read only memory (ROM) is hashed by the bootstrap code and the result is compared to an expected hash value maintained in the bootstrap code. Further verification of the boot-up process is carried out by the preloader, which hashes the code in ROM to obtain a hash value for the code. The result is verified against a digital signature value that defines an expected value for this hash. Failure to obtain any expected result terminates the boot-up process. Since the bootstrap code confirms the preloader, and the preloader confirms the remainder of the code in ROM, this technique is useful for ensuring that the code used for booting up the device has not been modified or replaced.

Use of hashing in a secure boot loader

A computing environment maintains the integrity of data stored in system memory. The system has a memory management unit that maintains a plurality of real page numbers. The system also comprises an address bus in communication with the memory management unit. The address bus comprises a plurality of address lines, wherein a value of at least one address line is set by a real page number from the memory management unit. The system has an operating system that controls memory usage by controlling the real page numbers stored in said page table that is accessed by the memory management unit. At least one security feature such as data encryption is selectively applied to data stored in a page of said memory as enabled by a value of said address line set by said real page number.

System and method for using address lines to control memory usage

An exemplary implementation of a security gateway for online console-based gaming operates as a gateway between a public network (e.g., the Internet), and a private network (e.g., an internal data center network). The security gateway allows secure communication channels to be established with game consoles via the public network, and allows secure communication between game consoles on the public network and service devices on the private network.

Security gateway for online console-based gaming

A secure key exchange with mutual authentication allows devices on a network to perform, in a single roundtrip over the network, the exchange. A key exchange initiator packet that does not include a key to be established is sent from an initiating device to another device via a network. The key exchange initiator packet is validated and the other device generates the key without requiring any additional packets to be received from the initiating device in order to generate the key. A key exchange response packet that does not include the key is returned to the initiating device, which validates the key exchange response packet and generates the key without requiring any additional packets to be sent to the other device or received from the other device.

Secure key exchange with mutual authentication

Attempts by drivers of a virtualized legacy computer game to communicate with nonexistent legacy game system hardware are converted into calls to actual hardware of the host computer game system. An access control list (ACL) restricting and/or reducing page permissions is used to explicitly forbid the drivers of the legacy computer game operating on the virtualized legacy computer game platform from writing to the MMIO addresses of the legacy computer game system. When the operating system of the virtualized legacy computer game platform attempts to touch its driver memory by writing to the MMIO addresses, the operating system of the host computer game system perceives a memory access violation, suspends the virtual machine implementing the virtualized computer game platform, and passes the intended write to an exception handler of the host operating system. The exception handler of the host operating system translates the attempted hardware access command into the command language of the host operating system and then returns control to the operating system of the virtualized legacy computer game platform. The legacy game is completely unaware of this address translation in that it sees only a successful hardware result and proceeds.

Virtual operating system device communication relying on memory access violations

A process for requesting authentication includes transmitting a hash digest formed from first client-specific data together with second client specific data and receiving, in response to transmitting, an indication of acceptance when the hash digest and second client-specific data correspond to a valid client authentication request.

Systems and methods for caching in authentication systems

An exemplary flexible network simulator and related methods test the ability of electronic devices to communicate with each other on a network, especially in real-time. The flexible network simulator can establish different connectivity protocols between multiple electronic devices and test the electronic devices using customized sets of network conditions.

Flexible network simulation tools and related methods

A integrity control system uses the address bits to enable encryption and/or protection of data stored in a system memory. The encryption and protection mechanisms are coupled to the CPU by way of a data bus and to the memory by way of a data bus. An address bus that determines the location of data to be stored or retrieved from system memory has a plurality of address lines. At least one of the address lines enabling the encryption mechanism to encrypt data before storage in the memory and to decrypt data after retrieval from memory. Another address line enables the protection mechanism to generate a hash of the data. The hash is stored and used to determine whether data has been altered while stored in system memory.

Growing community of inventors

Redmond, WA, United States of America

Dinarte R Morais