Help with C program and multiplying matrices

Okay, some background for what I am trying to accomplish. I have a key matrix that needs to be multiplied with the numerical value of the matrix that stores the plaintext. I'm not even sure how to make a 2d matrix with characters stored in them

this is the code I have:

#include #include #include

#define MAX 10000

int main() {

FILE *keyFile = fopen("one.txt", "r"); FILE *inputFile = fopen("two.txt", "r");

int i=0; int j=0; int key[10][10]; int keySize; char ch; char plainText[MAX];

//scan key grid size fscanf(keyFile,"%d", &keySize);

//print grid printf("Key: "); for(i=0; i

//setting counters back to 0; i=0; j=0;

//ch intakes characters from file //plaintext only prints lowercase characters printf(" Plaintext: "); while ((ch = fgetc(inputFile)) != EOF) {

if (ch>='a' && ch

fclose(inputFile); fclose(keyFile); return 0;

}

one.txt includes:

4 9 12 13 1 7 3 6 9 8 4 2 1 10 5 15 3

two.txt includes:

Security professionals have said for years that the only way to make a computer truly secure is for it to not be connected to any other computers, a method called airgapping. Then, any attack would have to happen physically, with the attacker actually entering the room and accessing the computer that way, which is incredibly unlikely. In the case of computers containing highly sensitive information, additional, physical security can always be added in the form of security guards, cameras, and so on.

Researchers at Georgia Institute of Technology have uncovered a vulnerability in all computers, however, which can be exploited regardless of an air gap. Its a vulnerability which youd never suspect, and its one thats hard to fight against. All CPUs emit electromagnetic signals when they are performing tasks, and the first thing these researchers discovered was that binary ones and zeroes emit different levels. The second thing they discovered is that electromagnetic radiation is also emitted by the voltage fluctuations and that it can be read from up to six meters away. These signals, by the way, are known as side-channels, and they are well-documented in the cryptography field.

The output is:

wsceafwvgznsacsihctehylsayiyanlevvrznraqaimmhdcajbjnuqowykyivehgkiztslktzvtlhxbb

lehmcpoddwkbnrmwpszcognnoxhsujopvehggfgfunbegpydafnalyubtzumbaryxctoolpkueyssrjy

cdyhojobqftmdqgbdfftfpcmptrlqblscygqqqdxwtlikntstkzynvmmvpysnfggiyyorwarxoifrocr

rcncuxmfjhrdnuqlnmwfonkzfaqrzcsxurclysqewceqsrudvehgixiljruwhapsojuzfyktsnyjyhwl

vrkceovbtuqheptotuqheqeyygyqfrognudutffdcjkvhektblwuzixkijszqyjnwsceafwvzvpdjjwu

nqqfwxruffhfxpkedwbggfgfxpqkrduinkpehormclniilpmejihjohafckdfanspsnorbauspqbypan

fmxwfpgccdibgdcrdqevwnmtyvwhdyqzyiusrivktliuywsytxpbihilgmtlonudnaxuhkxypwnahkql

mtcpzdugihctxighzgbyyjitpujkqnitbwpwwrsvvvkqpzzllwxwapqpkwkocnmxnnkwrdrpgvwblrtl

ybybnynehxqikxelwhtopgejztqwwxruaplojwfyihbunvmmtqqztfvrperkihifvkobcjypcxngpfie

ytgpolihmwfdkrcjkwkoebdcgdqzyqymixqhncybvbdnqksubaryhimvzptvjahmwbzifyrgmprwqgkk

edkrrojkpigzojqpqhqdrxlrzqtytrakzkfizjlbuijltoypwlshrrfjnqhmgxrkgzedkeooqpribrpd

rmyvbhwowplkkiakbwktopebrmcntrjpbcipirmbpwerlwfqotefguzlhxqixnsmyuwscauakrjiomfj

tounfowfrmrauhyhppnt

Ignore the spacing. I'm also wanting to split the program up into functions. I'm not sure how to do that when it comes to input file pointers. Any help is appreciated. Thank you

Each letter is numbered from 0 to 25. A B C D E FI G HI JK IL IM IN O P IQ R S T LU V WW Y Z 0 1 2 3 4 5 6 7 8 9 1 1 1 1 1 1 1 2 2 2 1 2 3 4 5 6 7 8 0 2 3 4 5 The phrase to encode is: LINEAR ALGEBRA IS SO EASY Divide the phrase into batches ofthree letters and convert them into matrix form as shown below: 1 8 11 B 1 8 O 14 18 N 13 R 17 G 6 R 17 18 E 24 Key matrix is: 3 10 20 A 20 9 17 9 4 17