/*
* Transposition cipher cracker
*
* Algorithm used to find keys:
*
* n = keylength
* t = textlength
* a = t / n
* b = t % n
* d = accumulated rest terms
* k = wanted plain text position
* loc(k) = a * perm(k % n) + d(perm(k % n)) + k/n
*
* By Ben Ruijl, 2009
*
* compile: g++ -O2 col.cpp
*/
#include <iostream>
#include <cstring>
#define MAXKEY 20
const char* buffer = "irtyhockeibtdaamoelatcnsronhoniirttcacdeiunsihaioarnndgpruphahirgtoarnmclspstwe";
int buflength;
const char* crib = "computer";
int criblength;
void print(int* perm, int n)
{
int a = buflength / n;
int b = buflength % n;
//invert perm
int invperm[MAXKEY];
for (int i = 0; i < n; i++)
invperm[perm[i]] = i;
int d[MAXKEY] = {0};
for (int i = 1; i < n; i++)
{
d[i] = d[i -1];
if (invperm[i - 1] < b)
d[i]++;
}
std::cout << "Found: ";
for (int i = 0; i < buflength; i++)
std::cout << buffer[a * perm[i % n] + d[perm[i % n]] + i / n];
std::cout << std::endl;
}
bool checkperm(int* perm, int n)
{
int cribpos = 0;
int a = buflength / n;
int b = buflength % n;
//invert perm
int invperm[MAXKEY];
for (int i = 0; i < n; i++)
invperm[perm[i]] = i;
int d[MAXKEY] = {0};
for (int i = 1; i < n; i++)
{
d[i] = d[i -1];
if (invperm[i - 1] < b)
d[i]++;
}
for (int i = 0; i < buflength; i++)
{
if (buffer[a * perm[i % n] + d[perm[i % n]] + i / n] n - 1)
checkperm(v, n);
else
{
for (int i = start; i < n; i++)
{
int tmp = v[i];
v[i] = v[start];
v[start] = tmp;
permute(v, start + 1, n);
v[start] = v[i];
v[i] = tmp;
}
}
}
int main(int argv, char** argc)
{
int perm[MAXKEY];
for (int i = 0; i < MAXKEY; i++)
perm[i] = i;
buflength = strlen(buffer);
criblength = strlen(crib);
int curkey = 2; // start key
while (curkey < MAXKEY)
{
std::cout << "Testing key " << curkey << std::endl;
permute(perm, 0, curkey); // permutate keys
curkey++;
}
return 0;
}
Just fart!
He decided to implement his plan.
Easy to test program Easier to implement programming solution Reduce the repeating code Easy to change and modify program Increase the productivity
implement it. enough said.
Explain The merits of using a deque to implement a stack in data structure
Just fart!
yes
The cipher made the intent of the message difficult to understand.
lund lelo mooh mein
pro c language to implement linear search using pointers
stack abstract datatype
Using a keyword as long as the message will make a vigenere cipher unbreakable.
ANSI/ISO C does not and never has done graphics.
He decided to implement his plan.
Easy to test program Easier to implement programming solution Reduce the repeating code Easy to change and modify program Increase the productivity
A VHDL program can be written to provide a password in the following ways.Using FPGA:Your program can be dumped into a FPGA. This works as per the program written. As the code is burned into it, the user can not see the code. Now, within your program you can have a conditional statement which serves as your password. For example,if (c=ramarav) then...................................................................Using CPLD:It also works in the similar manner.Using a GUI:We can implement a graphical user interface, but the easier way is to take the help of MATLAB tool. We can implement our VHDL code in MATLAB tool and it serves the purpose.
implement it. enough said.