Abstract: The present invention provides a system, method and device, for carrying out secure electronic communication over a computer network via a computer susceptible of being virus infected or eavesdropped by means of a personal apparatus comprising processing means, one or more memory devices, one or more interfacing means suitable for exchanging information with the insecure computer, and a communication software having cryptographic capabilities stored in the one or more memory means, wherein the personal apparatus is adapted to establish a secure channel with a remote computer over the computer network, by means of the insecure computer machine.

Abstract: A method for carrying out modular arithmetic computations involving multiplication operations by utilizing a non-reduced and extended Montgomery multiplication between a first A and a second B integer values, in which the number of iterations required is greater than the number of bits n of an odd modulo value N. The method comprises storing n+2 bit values in an accumulating device (S) capable of, of adding n+2 bit values (X) to it content, and of dividing its content by 2. Whenever desired, the content of the accumulating device is set to zero value.

Abstract: This invention discloses apparatus and methods for accelerating processing, loading and unloading of data, from and to a plurality of memory addresses in a CPU having an accumulator, and to a memory-mapped coprocessing device for continuous integer computations.

Abstract: This invention discloses a system for safe collection of payment in return for goods, values or services, the system including a multiplicity of electronic system elements wherein each individual one of the elements has a purse storing an amount of credit for value receivable granted to the individual system element, each purse including a purse monitor operative to sign and authenticate a transaction record of each transaction in which the purse uses some of the credit for value receivable which it has been granted, and a purse control unit operative to prevent the purse, off-line, from exceeding the credit for value receivable which it has been granted.

Abstract: A system for safe collection of payment by a vehicle operator from riders, the system including a multiplicity of electronic payment receipt generators, each operable by a vehicle operator, wherein each individual one of the payment receipt generators includes an electronic purse storing an amount of electronic cash, each electronic purse including an electronic cash loader operative to use some of the electronic cash to generate a payment receipt to be given by the vehicle operator to a rider, and an electronic purse control unit operative to prevent said electronic cash loader from exceeding said amount of electronic cash, thereby limiting the vehicle operator's entitlement to collect payments from riders, and an electronic cashier purse operative to increment the electronic purse of each electronic payment receipt generator by the amount of payment collected by the vehicle operator to whom the electronic payment receipt generator is assigned.

Abstract: A modular arithmetic method and microelectronic apparatus therefore, operative to perform a sequence of interleaved Montgomery type multiplications and squaring operations, involves performing a sequence of modular multiplications and squarings using only a single carry save adder. Each multiplication is operative to perform the equivalent of three natural integer multiplication operations using an anticipatory device to determine a Y0 value, such that a result is an exponentiation.

Abstract: A compact synchronous microelectronic peripheral machine for standard microprocessors with means for proper clocking and control, has as essential elements: three main subdivided, switched and clocked shift registers, B, S, and N; two only multiplexed serial/parallel multipliers; borrow detectors, ancillary subtractors and adders; delay registers and switching elements; all of which embody a totally integrated concurrent and synchronous process approach to modular multiplication, squaring, and exponentiation. A method for carrying out modular multiplication, wherein the multiplicand A, the multiplier B and the modul, N, comprise m characters of k bits each, the multiplier not being greater than the modulus, is also described, wherein the multiplicand can be much larger than the modulus. It is demonstrated how the device can be used as a large number processor in the normal field of numbers.

Abstract: A compact synchronous microelectronic peripheral machine for standard microprocessors with means for proper clocking and control, has as essential elements: three main subdivided, switched and docked shift registers, B, S, and N; two only multiplexed serial/parallel multipliers; borrow detectors, ancillary subtractors and adders; delay registers and switching elements; all of which embody a totally integrated concurrent and synchronous process approach to modular multiplication, squaring, and exponentiation. A method for carrying out modular multiplication, wherein the multiplicand A , the multiplier B and the modul, N, comprise m characters of k bits each, the multiplier not being greater than the modulus, is also described, wherein the multiplicand can be much larger than the modulus. It is demonstrated how the device can be used as a large number processor in the normal field of numbers.