Abstract: A secure write blocking circuit and method of operation thereof. The secure write blocking circuit includes enable and disable block input terminals coupled to a blocking circuit. The blocking circuit, such as a set/reset latch in a preferred embodiment, generates a block signal to prevent write access to a nonvolatile memory device, such as flash memory, in response to signals provided to the enable and disable input terminals. The secure write blocking circuit also includes an interrupt generator, coupled to the disable block input terminal, that generates an interrupt signal in response to a signal at the disable input terminal. In a related embodiment the secure write blocking circuit also includes a logic circuit, coupled to the blocking circuit, that receives the block signal and a write enable signal and in response thereto generates a control signal to a write enable input of the nonvolatile memory device.

Abstract: The disclosed methods enable users to securably modify system attributes of completed computer systems, without requiring that the system be returned to their manufacturer or that the system be “overhauled.” The methods of the present invention permit manufacturing cost savings and efficiencies, while allowing existing built inventory to be modified to meet current market demands without the need to recall built systems back to the origin of manufacture.

Abstract: The disclosed methods enable users to securably modify BIOS data blocks within an EEPROM to update and/or verify non-executable data without requiring that the entire EEPROM and segments thereof be available for open access.

Abstract: A system and method for access control of a hardfile responsive to a computer system having an operating system is disclosed. The method includes detecting a special boot condition during a pre-boot test of the computer system; and altering, in response to the special boot condition, an operating system access configuration of the hardfile. The system includes a computer system that adjusts an operating system access to a hardfile based upon various boot conditions.

Abstract: A method and system for updating a root of trust measurement (RTM) function in a personal computer is disclosed. The RTM function is located in a boot block of the personal computer. The method and system comprise initializing a request to update the RTM function and unlocking the boot block based on an authentication process. The method and system further includes updating the RTM function. Through the use of the method and system in accordance with the present invention, the RTM function in a personal computer is updated in a manner that ensures that the update is authentic.

Abstract: In a computer network including a plurality of interconnected computers, one of the computers being a sleeping computer in a power down state, the sleeping computer listening for a packet associated with the sleeping computer, a method and system of waking the sleeping computer from the computer network. An incoming packet of data is transmitted from one of the computers in the network to the sleeping computer. When the sleeping computer detects the incoming packet, it determines if the incoming packet contains a data sequence associated with the sleeping computer. Further, the sleeping computer compares a transit value in the incoming packet to a predetermined value stored at the sleeping computer. The transit value indicates how far the data packet has traveled through the network, indicating the approximate origin of the data packet. Knowing the approximate origin of the data packet allows the client system to identify if the data packet originated from an external network.

Abstract: A designated user of a computer system is allowed to conceal from access portions of information stored on a hard disk drive or comparable storage device. The program instructions which initiate operation of the computer system, sometimes also known as BIOS code, enable a designated user or an administrator to declare certain portions of information normally stored accessibly to the system to be concealed, hidden, or invisible to a technical support person having a lesser level of access. Certain partitions are made inaccessible to any operator lacking the password of a designated user or administrator. Instead, a separate password is provided which enables initiation of operation of the system for maintenance purposes using only partitions which are open or unconcealed.

Abstract: In a computer network including a plurality of interconnected computers, one of the computers being a sleeping computer in a power down state, the sleeping computer listening for a packet associated with the sleeping computer, a method of waking the sleeping computer from the computer network. An incoming packet of data is transmitted from an administration system in the network to the sleeping computer. When the sleeping computer detects the incoming packet, it determines if the incoming packet contains a data sequence associated with the sleeping computer. If the incoming packet matches the particular data sequence associated with the sleeping computer, the sleeping computer transmits a reply message to the administration system. Upon receiving the reply, the administration system modifies the reply message in a predetermined manner and transmits the modified reply to the sleeping computer.

Abstract: A tamper detection mechanism for a personal computer (PC) and a method of use thereof is disclosed. Accordingly, a first aspect of the present invention comprises a tamper detection mechanism. The tamper detection mechanism comprises a first Root-of Trust Measurement (RTM) module which is coupled to and fixed within the PC, a second RTM module being removably attached to the PC and a diagnostic program for comparing a copy of the first RTM module with a copy of the second RTM module to determine whether the first RTM module is valid. A second aspect of the present invention comprises a method of provided tamper detection for a PC. The method comprises providing a first RTM module, providing a second RTM module and utilizing a diagnostic program to compare a copy of the first RTM module with the a copy of the second module to determine whether the first RTM module is valid.

Abstract: A computer system contains selectively available boot block codes. A first boot block is of the conventional type and is stored in storage media such as flash ROM on a system planar with the processor of the computer system. A second boot block is located on a feature card and contains an immutable security code in compliance with the Trusted Computing Platform Alliance (TCPA) specification. The boot block on the feature card is enabled if the first boot block detects the presence of the feature card. The computer system can be readily modified as the computer system is reconfigured, while maintaining compliance with the TCPA specification. A switching mechanism controls which of the boot blocks is to be activated. The feature card is disabled in the event of a computer system reset to prevent access to the TCPA compliant code and function.

Abstract: A method for providing security in password-based access to computer networks, the network including a server and a remote user, includes: signing a phrase by a security chip of the server using an encryption key; associating the signed phrase with the remote user; signing the phrase with an encryption key obtained by the security chip when a request for access to the computer network is received from the remote user; comparing the phrase signed with the obtained encryption key with the signed phrase associated with the remote user; and granting access to the remote user if the phrase signed with the obtained encryption key is the same as the stored signed phrase associated with the remote user. The use of the encryption key protects against “dictionary attacks”. Use of the security chip protects against offline attacks. These provide greater security for the computer network.

Abstract: A method, system and computer readable medium containing programming instructions for detecting a tamper event in a computer system having an embedded security system (ESS), a trusted operating system, and a plurality of devices is disclosed. The method, system and computer readable medium of the present invention provide for receiving a tamper signal in the ESS, and locking the tamper signal in the ESS. According to the method, system and computer readable medium of the present invention, the trusted operating system is capable of detecting the tamper signal in the ESS.

Abstract: A method, system and computer readable medium containing programming instructions for booting a computer system having a plurality of devices is disclosed. They include provisions for initiating a boot sequence in the computer system and determining whether a device of the plurality of devices is either a bootable device or a nonbootable device. If the device is a nonbootable device, a clean restart of the boot sequence is performed, wherein the nonbootable device is bypassed during the clean restart.

Abstract: A method, system and computer readable medium containing programming instructions for tracking a secure boot in a computer system having a plurality of devices is disclosed. The method, system and computer readable medium include providing an embedded security system (ESS) in the computer system, wherein the ESS includes at least one boot platform configuration register (PCR) and a shadow PCR for each of the at least one boot PCRs, initiating a platform reset to boot the computer system via BIOS, and, for a device booted, generating a measurement value for the device and extending that value to one of the at least one boot PCRs and its corresponding shadow PCR. The system, method and computer readable medium of the present invention also includes comparing the measurement values of the boot PCRs to their corresponding shadow PCRs, whereby the computer system is trusted if the measurement values match.

Abstract: A secure write blocking circuit and method of operation thereof. The secure write blocking circuit includes enable and disable block input terminals coupled to a blocking circuit. The blocking circuit, such as a set/reset latch in a preferred embodiment, generates a block signal to prevent write access to a nonvolatile memory device, such as flash memory, in response to signals provided to the enable and disable input terminals. The secure write blocking circuit also includes an interrupt generator, coupled to the disable block input terminal, that generates an interrupt signal in response to a signal at the disable input terminal. In a related embodiment the secure write blocking circuit also includes a logic circuit, coupled to the blocking circuit, that receives the block signal and a write enable signal and in response thereto generates a control signal to a write enable input of the nonvolatile memory device.

Abstract: Personal computer (PC) systems that are remotely managed are equipped with protected storage that is accessible only by Basic Input Output System (BIOS) code. The protected storage has the capacity to store a symmetrical encryption Key. An electronically erasable programmable read only memory (EEPROM) which normally contains the BIOS code is used to store accessible configuration data as well as previously remotely unaccessible sensitive access information (e.g., passwords). The EEPROM is write protected with standard write protect algorithms and access the alterable EEPROM data is through write requests to the BIOS code. Previously remotely unaccessible sensitive data is encrypted with the symmetrical encryption Key by the BIOS code. Remote access to the sensitive data is accomplished via change requests submitted to the BIOS code over a secure channel. The BIOS code has data that allows it to determine if the request is valid.

Abstract: When a flash unlock routine unlocks the flash memory to permit updating of a BIOS image, a message is left in secure non-volatile memory, such as a EEPROM. Upon the next re-boot, the boot block code will detect the special message in the non-volatile memory and perform a signature verification of the next block of code that is to be executed during the POST process. This code block will check the remainder of the BIOS image before POST proceeds.

Abstract: An update utility requests a signature verification of the utility's signature along with a request to unlock the flash memory stored in the utility. A trusted platform module (“TPM”) performs a signature verification of the utility using a previously stored public key. Upon verification of the signature, the TPM unlocks the flash memory to permit update of the utility. Upon completion of the update, the flash utility issues a lock request to the TPM to relock the flash memory.

Abstract: An SMI (System Management Interrupt) generation capability is added to the cryptographic verification operation utilized to verify an update of a system management utility, such as the BIOS update utility. With the addition of an SMI upon completion of a signature verification command, the SMI handler issues a signature verification request to a trusted platform module (TPM) and returns control to the controlling application with a status code indicating it should begin polling the SMI handler for status. Upon completion of the verification operation, the TPM issues the SMI. The SMI handler then queries the TPM for status. The SMI handler then updates its internal status and permits access to the requested resource assuming the verification is successful. Upon the next poll from the application, the SMI handler returns the status to the calling application, which would either continue or abort with the update operation.

Abstract: A data processing system and method of password protecting the boot of a data processing system are disclosed. According to the method, in response to an attempt to boot the data processing system utilizing a boot device, the boot device is interrogated for a password. If the boot device supplies password information corresponding to that of a trusted boot device, the data processing system boots utilizing the boot device. If, however, the boot device does not supply password information corresponding to that of a trusted boot device, booting from the boot device is inhibited. In a preferred embodiment, the password information comprises a unique combination of the boot device's manufacturer-supplied model and serial numbers.