古典密码中,主要的思想为移位算法及置换算法。 1.移位密码 密钥K为整数,且取值空间为0到25;加密函数:x = x + k (mod 26);解密函数:x = x - k (mod 26)。当K=3时,为凯撒密码。 2.仿射密码 密钥对由a、b组成,整数a满足 gcd(a, 26) = 1,整数b的取值空间为0到25;加密函数:x = ax + b(mod 26);解密函数:x = a*y - a*b (mod 26)。当a=1,b=3时,为凯撒密码。 3.维吉尼亚密码 首先确定密钥长度(本例中密钥只采取个位数字,所以取决于输入密钥的长度),然后输入满足这个长度的向量;加密:取明文第一个字母并将之移k1位,这里k1=1,第二个字母移k2位,k2=2,一旦到了密钥末尾,又从头开始。 4.换位密码 首先确定密钥长度,输入长度为5的0到4的整数序列,将明文分成每5个字母一组,每组字母按照密钥进行换位。
标签: 密码
上传时间: 2016-02-09
上传用户:jqy_china
DirectX not only provides fast access to the hardware and therefore incredibly speedy performance, but it also makes it much easier for hardware developers to produce new devices that work well in the Windows environment. The DirectX APIs take away the necessity of writing your own low-level, device-specific code to access hardware such as the display adapter and network card, making it much easier for you to write programs that take full advantage of the computer s multimedia capabilities.
标签: performance incredibly therefore hardware
上传时间: 2016-02-16
上传用户:秦莞尔w
On Sunday, April 27, 2003, Fresno will celebrate Earth Day in downtown Fresno at Courthouse Park. The event will begin at noon. This year we will include music, speakers, and vendors, plus activities for children. Fresno Earth Day is recognized as the only Earth Day festival that happens in Fresno, and the largest in the Central Valley. The Fresno Earth Day Committee is a small group of environmental activists hoping to broaden the appeal of a better planet and environment. We are a non-profit organization whose fiscal fiduciary is the Fresno Center for Nonviolence.
标签: Fresno Courthouse celebrate downtown
上传时间: 2016-02-24
上传用户:cursor
Generate 100 samples of a zero-mean white noise sequence with variance , by using a uniform random number generator. a Compute the autocorrelation of for . b Compute the periodogram estimate and plot it. c Generate 10 different realizations of , and compute the corresponding sample autocorrelation sequences , and . Compute the average autocorrelation sequence as and the corresponding periodogram for . d Compute and plot the average periodogram using the Bartlett method. e Comment on the results in parts (a) through (d).
标签: zero-mean Generate sequence variance
上传时间: 2016-03-04
上传用户:朗朗乾坤
中心点漂移是一种非监督聚类算法(与k-means算法相似,但应用范围更广些),可用于图像分割,基于Matlab实现的源码。 MedoidShift is a unsupervised clustering algorithm(similar to k-means algorithm, but can be used in border application fields), can be used for image segmentation. Included is the Matlab implementation source code.
上传时间: 2016-03-28
上传用户:wab1981
高效的k-means算法实现,使用了k-d树与局部搜索等提高k-means算法的执行效率,同时包含示例代码,用c++代码实现。 Effecient implementation of k-means algorith, k-d tree and local search strategy are implementd to improve the effeciency, samples are included to show how to use it. All codes are implemented in C++.
上传时间: 2016-03-28
上传用户:yulg
k-meansy算法源代码。This directory contains code implementing the K-means algorithm. Source code may be found in KMEANS.CPP. Sample data isfound in KM2.DAT. The KMEANS program accepts input consisting of vectors and calculates the given number of cluster centers using the K-means algorithm. Output is directed to the screen.
标签: code implementing directory algorithm
上传时间: 2016-04-07
上传用户:shawvi
Atheros无线芯片AR-6000系列wince 6驱动源代码(这东西我也没用过别问我,我是搜别的wince资源搜到的) AR6K SDIO support. Requires firmware 1.1 on SD13 cards. readme: Atheros Communications AR6001 WLAN Driver for SDIO installation Read Me March 26,2007 (based on k14 fw1.1) Windows CE Embedded CE 6.0 driver installation. 1. Unzip the installation file onto your system (called installation directory below) 2. Create an OS design or open an existing OS design in Platform Builder 6.0. a. The OS must support the SD bus driver and have an SD Host Controller driver (add these from Catalog Items). b. Run image size should be set to allow greater than 32MB. 3. a. From the Project menu select Add Existing Subproject... b. select AR6K_DRV.pbxml c. select open This should create a subproject within your OS Design project for the AR6K_DRV driver. 4. Build the solution. 转自Tony嵌入式,原文地址:http://www.cevx.com/bbs/dispbbs.asp?boardID=4&ID=11762&page=1
标签: wince Requires firmware Atheros
上传时间: 2014-11-11
上传用户:bibirnovis
this a 8-bit risc micro process,Th eM C Ud esignedis c ompatiblew ith PIC16C57 o microchip Technology Inc.in the instruction system
标签: ompatiblew Technolog esignedis microchip
上传时间: 2014-01-14
上传用户:xinyuzhiqiwuwu
CRC16算法的Java实现,使用方法如下: CRC16 crc16 = new CRC16() byte[] b = new byte[] { // (byte) 0xF0,(byte)0xF0,(byte)0xF0,(byte)0x72 (byte) 0x2C, (byte) 0x00, (byte) 0xFF, (byte) 0xFE, (byte) 0xFE, (byte) 0x04, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00 } for (int k = 0 k < b.length k++) { crc16.update(b[k]) } System.out.println(Integer.toHexString(crc16.getValue())) System.out.println(Integer.toHexString(b.length))
上传时间: 2014-12-20
上传用户:ve3344