tailieunhanh - Hacker Professional Ebook part 190

Tham khảo tài liệu 'hacker professional ebook part 190', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | factoring research. Another possibility is that someone will prove that factoring is difficult. This negative breakthrough is probably more likely than the positive breakthrough discussed above but would also be unexpected at the current state of theoretical factoring research. This development would guarantee the security of RSA beyond a certain key size. What is the RSA Factoring Challenge RSA Data Security Inc. RSADSI administers a factoring contest with quarterly cash prizes. Those who factor numbers listed by RSADSI earn points toward the prizes factoring smaller numbers earns more points than factoring larger numbers. Results of the contest may be useful to those who wish to know the state of the art in factoring the results show the size of numbers factored which algorithms are used and how much time was required to factor each number. Send e-mail to challenge-info@ for information. What is the discrete log problem The discrete log problem in its most common formulation is to find the exponent x in the formula y gAx mod p in other words it seeks to answer the question To what power must g be raised in order to obtain y modulo the prime number p There are other more general formulations as well. Like the factoring problem the discrete log problem is believed to be difficult and also to be the hard direction of a one-way function. For this reason it has been the basis of several public-key cryptosystems including the ElGamal system and DSS see Questions and . The discrete log problem bears the same relation to these systems as factoring does to RSA the security of these systems rests on the assumption that discrete logs are difficult to compute. The discrete log problem has received much attention in recent years descriptions of some of the most efficient algorithms can be found in 47 21 and 33 . The best discrete log problems have expected running times similar to that of the best factoring algorithms. Rivest 72 has analyzed the .