System Security : C code for Hill Cipher (should be executed in linux with gcc).

//Aim:To implement Hill Cipher in C //Program: #include<stdio.h> int check(int x) { if(x%3==0) return 0; int a=x/3; int b=3*(a+1); int c=b-x; return c; } void main() { int l,i,j; int temp1; int k[3][3]; int p[3][1]; int c[3][1]; char ch; printf("\nThe cipher has a key of length 9. ie. a 3*3 matrix.\nEnter the 9 character key. "); for(i=0;i<3;++i) { for(j=0;j<3;++j) { scanf("%c",&ch); if(65<=ch && ch<=91) k[i][j]=(int)ch%65; else k[i][j]=(int)ch%97; } } for(i=0;i<3;++i) { for(j=0;j<3;++j) { printf("%d ",k[i][j]); } printf("\n"); } printf("\nEnter the length of string to be encoded(without spaces). "); scanf("%d",&l); temp1=check(l); if(temp1>0) printf("You have to enter %d bogus characters.",temp1); char pi[l+temp1]; printf("\nEnter the string. "); for(i=-1;i<l+temp1;++i) { scanf("%c",&pi[i]); } int temp2=l; int n=(l+temp1)/3; int temp3; int flag=0; int count; printf("\n\nThe encoded cipher is : "); while(n>0) { count=0; for(i=flag;i<flag+3;++i) { if(65<=pi[i] && pi[i]<=91) temp3=(int)pi[i]%65; else temp3=(int)pi[i]%97; p[count][0]=temp3; count=count+1; } int k1; for(i=0;i<3;++i) c[i][0]=0; for(i=0;i<3;++i) { for(j=0;j<1;++j) { for(k1=0;k1<3;++k1) c[i][j]+=k[i][k1]*p[k1][j]; } } for(i=0;i<3;++i) { c[i][0]=c[i][0]%26; printf("%c ",(char)(c[i][0]+65)); } n=n-1; flag=flag+3; } } /*OUTPUT [adi@localhost Desktop]$ gcc hill.c [adi@localhost Desktop]$ ./a.out The cipher has a key of length 9. ie. a 3*3 matrix. Enter the 9 character key. GYBNQKURP 6 24 1 13 16 10 20 17 15 Enter the length of string to be encoded(without spaces). 6 Enter the string. actCAt The encoded cipher is : P O H F I N [adi@localhost Desktop]$ gcc hill.c [adi@localhost Desktop]$ ./a.out The cipher has a key of length 9. ie. a 3*3 matrix. Enter the 9 character key. GYBNQKURP 6 24 1 13 16 10 20 17 15 Enter the length of string to be encoded(without spaces). 7 You have to enter 2 bogus characters. Enter the string. actcatact The encoded cipher is : P O H F I N P O H */

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Robotics & AI: Java code for Homogeneous Composite Transformation Matrix (HCTM) finding fixed , mobile co-ordinates.

//Aim: To implement fixed and mobile co-ordinates in JAVA //Program import java.util.*; class htmc { static int m1[][]={ {3,0,0},{0,2,1},{0,-1,2}}; static int m2[][]={ {2,0,-1},{0,3,0},{1,0,2}}; static int m3[][]={ {2,1,0},{-1,2,0},{0,0,3}}; static double pm[][]=new double[3][1]; static double pf[][]=new double[3][1]; static double p[][]=new double[3][3]; static int a,t; static void mat_mul() { for(int i=0;i<3;++i) pf[i][0]=0; for(int i=0;i<3;++i) { for(int j=0;j<1;++j) { for(int k=0;k<3;++k) pf[i][j]+=p[i][k]*pm[k][j]; } } } static void get_m1() { double temp; for(int i=0;i<3;++i) { for(int j=0;j<3;++j) { if(m1[i][j]==2) p[i][j]=Math.cos(Math.toRadians(t)); else if(m1[i][j]==3) p[i][j]=1; else { temp=90+m1[i][j]*t; p[i][j]=Math.cos(Math.toRadians(temp)); } } } } static void get_m2() { double temp; for(int i=0;i<3;++i) { for(int j=0;j<3;++j) { if(m2[i][j]==2) p[i][j]=Math.cos(Math.toRadians(t)); else if(m2[i][j]==3) p[i][j]=1; else { temp=90+m2[i][j]*t; p[i][j]=Math.cos(Math.toRadians(temp)); } } } } static void get_m3() { double temp; for(int i=0;i<3;++i) { for(int j=0;j<3;++j) { if(m3[i][j]==2) p[i][j]=Math.cos(Math.toRadians(t)); else if(m3[i][j]==3) p[i][j]=1; else { temp=90+m3[i][j]*t; p[i][j]=Math.cos(Math.toRadians(temp)); } } } } public static void main(String args[]) { Scanner scr=new Scanner(System.in); System.out.println("Enter [P]m values. "); for(int i=0;i<3;++i) { pm[i][0]=scr.nextDouble(); } System.out.println("Rotation about which axis? 1,2,3 "); a=scr.nextInt(); System.out.println("Enter the angle "); t=scr.nextInt(); if(a==1) get_m1(); else if(a==2) get_m2(); else get_m3(); mat_mul(); System.out.println("The [P]f matrix is as follows. "); for(int i=0;i<3;++i) System.out.println(pf[i][0]); int temp1; for(int i=0;i<3;++i) { for(int j=0;j<3;++j) { p[i][j]=(p[i][j]*100); temp1=(int)p[i][j]; p[i][j]=temp1/100.0; } } System.out.println("\nThe final HTMC matrix is as follows."); for(int i=0;i<3;++i) { for(int j=0;j<3;++j) { System.out.print(p[i][j]+"\t"); } System.out.print(pm[i][0]+"\n"); } System.out.print("\n0\t0\t0\t1"); } } /*OUTPUT C:\Users\Aditya\Desktop\aditya>javac htmc.java C:\Users\Aditya\Desktop\aditya>java htmc Enter [P]m values. 2 0 3 Rotation about which axis? 1,2,3 1 Enter the angle 60 The [P]f matrix is as follows. 2.0 -2.598076211353316 1.5000000000000007 The final HTMC matrix is as follows. 1.0 0.0 0.0 2.0 0.0 0.5 -0.86 0.0 0.0 0.86 0.5 3.0 0 0 0 1 */

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System Security : C code for Additive cipher / Shift cipher / Caeser cipher ( can be executed in Linux )

In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plain text is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on. The method is named after Julius Caeser, who used it in his private correspondence.
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Given below is the C code for the same.

//Aim: To implement additive cipher in C //Program: #include<stdio.h> void main() { char c[20]; int a1[20]; int a2[20]; int n=0; int k=0; printf("\nPlease Enter the key value: "); scanf("%d",&k); printf("\nHow many letters in the text? : "); scanf("%d",&n); int i; printf("\nPlease enter a word to be encoded:"); for(i=-1;i<n;++i) { scanf("%c",&c[i]); } int temp=0; int j=0; int count=0; for(i=0;i<=n;++i) { l1:temp=(int)c[i]; if(c[i]==' ') { i=i+1; count=count+1; goto l1; } if(65<=temp && temp<=91) a1[j]=temp%65; else if(97<=temp<=123) a1[j]=temp%97; a2[j]=(a1[j]+k)%26; ++j; } n=n-count; printf("\nThe encoded cipher is: "); char c2[20]; for(i=0;i<n;++i) { c2[i]=(char)(a2[i]+97); printf("%c",c2[i]); } printf("\n\nDecoding it receiver side "); int a3[20]; for(i=0;i<n;++i) a3[i]=(int)(c2[i]-97); for(i=0;i<n;++i) { if(a3[i]>=k) a3[i]=a3[i]-k; else a3[i]=a3[i]-15+26; } printf("\nThe text is: "); for(i=0;i<n;++i) { printf("%c",(char)(a3[i]+97)); } } /*OUTPUT Please Enter the key value: 15 How many letters in the text? : 5 Please enter a word to be encoded:hello The encoded cipher is: wtaad Decoding it receiver side The text is: hello Please Enter the key value: 15 How many letters in the text? : 12 Please enter a word to be encoded:good morning The encoded cipher is: vddsbdgcxcv Decoding it receiver side The text is: goodmorning */

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SEM 7 [Revised] Syllabus for Computer engineering (MU) Free Download

 Use the download box to download the Syllabus copy for SEM 7.

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Everything about SEM 6 (Computer Engineering)

This is an extremely important and useful post for sem 6 computer enginering students.
Download the "Everything for SEM 6.zip" file from the download box in the blog.

It contains all the assignments, experiments, important notes,  for the following,
1.OOSE
2.AMP
3.SPCC
4.ACN
5.DWM
6.SEMINAR( topic:web personalization)

Download this file and you can complete all your term work with great ease and feel free to comment if you find it useful.So just download the file "Everything for SEM 6.zip" file from the download box.
Best of luck for your SEM 6 !!
The blog also provides Java codes for all experiments of sem 6.

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