At+t Corp.

Safenet, Inc.

Lucent Technologies Inc.

Michael M Kaplan

Timothy Ober

Peter Reed

Richard Vandervoort Cox

Daniel Nelson Heer

Bruce E McNair

Ernest M Bevilacqua

David P Maher

Andrew Frederick Bulfer

Wayne T Driscoll

Joseph P Randolph

Carol A Wegrzynowicz

Robert W Doud

David W Faucher

Lewis F Travis

A secure communication platform on an integrated circuit is a highly integrated security processor which incorporates a general purpose digital signal processor (DSP), along with a number of high performance cryptographic function elements, as well as a PCI and PCMCIA interface. The secure communications platform is integrated with an off-the-shelf DSP so that a vendor who is interested in digital signal processing could also receive built-in security functions which cooperate with the DSP. The integrated circuit includes a callable library of cryptographic commands and encryption algorithms. An encryption processor is included to perform key and data encryption, as well as a high performance hash processor and a public key accelerator.

Cryptographic co-processor

A kernel mode protection circuit includes a processor, a program counter, a kernel program fetch supervisor circuit, a kernel data fetch supervisor circuit, a program memory, a data memory, a flip-flop circuit and two AND circuits. The data memory includes two user memories, protected registers and random access memory (RAM). The program memory includes two user memories and a kernel read only memory (ROM). The circuit may operate in either a user mode (kernel ROM is not accessible) or a kernel mode (kernel ROM is accessible). When in the kernel mode the kernel RAM and certain protected registers are accessible only by a secure kernel. The kernel mode control circuit will reset the processor should a security violation occur, such as attempting to access the kernel RAM while in the user mode. The kernel program fetch supervisor circuit monitors and compares an address within the program counter to a predetermined address, stored within the kernel program fetch supervisor circuit, to determine if a security violation has occurred. The kernel data fetch supervisor circuit monitors and compares the data address to addresses defining a protected memory area. A security violation will occur if the data address is within the protected memory address range and the processor will be reset. A method of kernel mode protection includes the step of fetching a program opcode. If the program opcode is from the kernel memory, the processor is reset. If the program opcode is from a user memory, then the processor may fetch the data operand. If the data operand is fetched from the kernel memory, the processor is reset. If the data operand is fetched from a user memory, the processor is permitted to enter the kernel memory. If a program opcodes is fetched from the kernel memory the processor may continue to fetch operands from either the kernel memory or the data memory. The processor remains in kernel mode and continues to fetch program opcodes until all of the opcodes have been fetched, or until an opcode fetched is from the user memory. If an opcode fetched is from the user memory, the processor switches back to user mode.

Kernel mode protection

A protection circuit operates in a user or kernel mode. In the kernel mode, a kernel memory is accessible only by a secure kernel. A processor is reset if a security violation occurs, such as by attempting to access kernel memory in user mode. A program fetch supervisor circuit compares addresses to a predetermined address to determine if a security violation has occurred. A data fetch supervisor circuit compares data addresses to a protected memory address range. A security violation occurs if the data address is in protected memory, which resets the processor. A method of kernel mode protection includes fetching a program opcode or data operand. If the program opcode or data operand is from kernel memory and the processor is in user mode, the processor is reset. If an opcode is fetched from user memory while in kernel mode, the processor reverts to user mode.

A security node disposed in the telecommunications network connecting calling and called parties transforms information (which can be voice, data, facsimile, video and other types of calls or messages) encrypted in a first format to (a) encrypted information in a different format or to (b) non-encrypted information, and vice-versa. The node is accessible from any location connected to the network. By routing calls or messages originated by the calling party and destined for the called party via the security node, and providing appropriate control signals to the node, the information may be encrypted only over a portion of the transmission path between the parties, and clear over the remainder of the transmission path. Alternatively, the information may be encrypted in different portions of the path using different encryption algorithms. This arrangement enables the parties to obtain relatively secure communications even if only one party has a security device at the originating or terminating end, or if the parties have security devices using different handshaking protocols and encryption algorithms.

Secure telecommunications

Telephone security device

Growing community of inventors

Rockport, MA, United States of America

Michael M Kaplan