Cryptography in C and C++ (2nd Edition)
Michael Welschenbach, David Kramer
Format: PDF / Kindle (mobi) / ePub
This book covers everything you need to know to write professional-level cryptographic code. This expanded, improved second edition includes about 100 pages of new material as well as numerous improvements to the original text.
The chapter about random number generation has been completely rewritten, and the latest cryptographic techniques are covered in detail. Furthermore, this book covers the recent improvements in primality testing.
Remainder of the division. At the digit am+n the variable r_l is initialized to 0. The pointer qptr_l is set to the highest quotient digit. msdptrb_l = MSDPTR_L (b_l); msdptrr_l = MSDPTR_L (r_l) + 1; lsdptrr_l = MSDPTR_L (r_l) - DIGITS_L (b_l) + 1; *msdptrr_l = 0; qptr_l = quot_l + DIGITS_L (r_l) - DIGITS_L (b_l) + 1; We now enter the main loop. The pointer lsdptrr_l runs over the digits am , am−2 , . . . , a0 of the dividend in r_l, and the (implicit) index i over the values i = m + n, . . . ,.
The mid 1970s. It was truly a revolution: We know today that things are possible that previously we hadn’t even dared to think about. Diffie and Hellman were the first to formulate publicly the vision that secure communication must be able to take place spontaneously. Earlier, it was the case that sender and receiver had first to engage in secret communication to establish a common key. Diffie and Hellman asked, with the naivety of youth, whether one could communicate secretly without sharing a.
.4 That the calculation of axy from ax and ay in a finite cyclic group (the Diffie–Hellman problem) is just as difficult as the calculation of discrete logarithms and thus equivalent to this problem is, in fact, conjectured but has not been proved. To ensure the security of the procedure under these conditions the modulus p must be chosen sufficiently large (at least 1024 bits, better 2048 or more; see Table 17-1), and one should ensure that p − 1 contains a large prime divisor close to (p − 1)/2.
(length of the generated byte vector) Return: pointer to the calculated byte vector NULL, if in len the null pointer was passed Finally, for the transformation of unsigned values into the CLINT numerical format the two functions u2clint_l() and ul2clint_l() can be used. The function u2clint_l() converts USHORT arguments, and the function ul2clint_l() converts ULONG arguments, into the CLINT numerical format. The function ul2clint_l() will be described in the following as an example. 152.
Primacy is due her under all circumstances. —Carl Friedrich Gauss WHY DO WE NEED A book on cryptography whose principal focus is the arithmetic of whole numbers—the integers—and its application to computer programming? Is this not a rather insignificant subject in comparison to the important problems with which computer science generally involves itself? So long as one confines oneself to the range of numbers that can be represented by the standard numerical types of a programming language,.