B - Attack at the Orbit Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Practice URAL 1942 Description Combat spaceship “Rickenbacker” was approaching planet Orkut, the last citadel of the enemy race Shodan.…

http://www.bnuoj.com/bnuoj/problem_show.php?pid=27987 [题意]:给定坐标输出图形 [题解]:处理坐标上的小技巧 [code]: #include <iostream> #include <stdio.h> #include <string.h> #include <math.h> using namespace std; #define N 100 ][N*]; void init() { int i,j…

D - Record of the Attack at the Orbit Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Practice URAL 1944 Description The long-range laser at the board of combat spaceship “Rickenbacker” had successfully dest…

https://baike.baidu.com/item/UDP%20flood/5504851 UDPFlood是日渐猖厥的流量型DoS攻击,原理也很简单.常见的情况是利用大量UDP小包冲击DNS服务器或Radius认证服务器.流媒体视频服务器.100k bps的UDPFlood经常将线路上的骨干设备例如防火墙打瘫,造成整个网段的瘫痪.由于UDP协议是一种无连接的服务,在UDPFLOOD攻击中,攻击者可发送大量伪造源IP地址的小UDP包.但是,由于UDP协议是无连接性的,所以只要开了一个UDP…

标题来源:URAL 1141. RSA Attack 意甲冠军:给你e n c 并有m^e = c(mod n) 求 m 思路:首先学习RSA算法 here 过程大致是 1.发送的信息是m 2.随机选择两个质数 p和q, n = q*p, n的欧拉函数值φ(n)= (p-1)*(q-1)这个须要证明 3.选择一个与φ(n)互质的而且小于φ(n)的数e, 计算c = m^e(mod n) 4.发送c 5解密 求e的逆元d 逆元就是2个数乘一下在mod一个数等于1 这里就是e*d = 1(mod φ…

1141. RSA Attack Time limit: 1.0 secondMemory limit: 64 MB The RSA problem is the following: given a positive integer n that is a product of two distinct odd primes p and q, a positive integer e such that gcd(e, (p-1)*(q-1)) = 1, and an integer c, fi…

http://acm.timus.ru/problem.aspx?space=1&num=1557 1557. Network Attack Time limit: 2.0 secondMemory limit: 64 MB In some computer company, Mouse Inc., there is very complicated network structure. There are a lot of branches in different countries, so…

题目链接 题意 : 给你n,e,c,并且知道me ≡ c (mod n),而且n = p*q,pq都为素数. 思路 : 这道题的确与题目名字很相符,是个RSA算法,目前地球上最重要的加密算法.RSA算法原理 . 看到这个算法之后,就知道这个题是求cd≡m(mod n),要求m,就要先求d,而d则是e的模反元素. 如果两个正整数a和n互质,那么一定可以找到整数b,使得 ab-1 被n整除,或者说ab被n除的余数是1.这时,b就叫做a的模反元素. 由模反元素可知,ed≡1(mod Phi[n])(p…

The statement of this problem is very simple: you are to determine how many squares of the chessboard can be attacked by a knight standing alone on the board. Recall that a knight moves two squares forward (horizontally or vertically in any direction…

#1) HULK Description: HULK stands for HTTP Unbearable Load King. It is a DoS attack tool for the web server. It is created for research purposes. Features: It can bypass the cache engine. It can generate unique and obscure traffic. It generates a gre…