Search results
Results from the WOW.Com Content Network
In computing, a linear-feedback shift register (LFSR) is a shift register whose input bit is a linear function of its previous state. The most commonly used linear function of single bits is exclusive-or (XOR). Thus, an LFSR is most often a shift register whose input bit is driven by the XOR of some bits of the overall shift register value.
The generator is a Galois-type shift register with XOR gates placed according to powers (white numbers) of x in the generator polynomial. The message stream may be any length. After it has been shifted through the register, followed by 8 zeroes, the result in the register is the checksum. Checking received data with checksum.
Others have mentioned this, but to summarize: the Galois and Fibonacci LFSR should have the numbering of their taps reversed. Specifications like USB define Galois polynomials e.g. x^16 + x^5 + x^4 + x^3 + 1 which corresponds to taps at 16, 5, 4, 3. However, for industry, this is defined for a Galois LFSR with numbering starting from the left.
In their paper, [1] Meier and Steffelbach prove that a LFSR-based self-shrinking generator with a connection polynomial of length L results in an output sequence period of at least 2 L/2, and a linear complexity of at least 2 L/2-1. Furthermore, they show that any self-shrinking generator can be represented as a shrinking-generator.
It is a very fast sub-type of LFSR generators. Marsaglia also suggested as an improvement the xorwow generator, in which the output of a xorshift generator is added with a Weyl sequence. The xorwow generator is the default generator in the CURAND library of the nVidia CUDA application programming interface for graphics processing units.
The Berlekamp–Massey algorithm is an algorithm that will find the shortest linear-feedback shift register (LFSR) for a given binary output sequence. The algorithm will also find the minimal polynomial of a linearly recurrent sequence in an arbitrary field .
In cryptography, the shrinking generator is a form of pseudorandom number generator intended to be used in a stream cipher.It was published in Crypto 1993 by Don Coppersmith, Hugo Krawczyk and Yishay Mansour.
Refractive surgery is an optional eye surgery used to improve the refractive state of the eye and decrease or eliminate dependency on glasses or contact lenses. This can include various methods of surgical remodeling of the cornea (keratomileusis), lens implantation or lens replacement.