diff --git a/Makefile b/Makefile
index 9d3cb0d..d048279 100644
--- a/Makefile
+++ b/Makefile
@@ -4,10 +4,10 @@ OUTPUT_DIR = ./bin
 OUTPUT = -o ${OUTPUT_DIR}/PROG
 
 build: output_dir
-	gcc -Wall ${LIBRARIES} ${SOURCES} ${OUTPUT:PROG=crc}
+	gcc -Wall -pthread ${LIBRARIES} ${SOURCES} ${OUTPUT:PROG=crc}
 
 debug: output_dir
-	gcc -Wall -g ${LIBRARIES} ${SOURCES} ${OUTPUT:PROG=crc}
+	gcc -Wall -g -pthread ${LIBRARIES} ${SOURCES} ${OUTPUT:PROG=crc}
 
 output_dir:
 	mkdir -p ${OUTPUT_DIR}
diff --git a/cmd/crc.c b/cmd/crc.c
index 0708625..147f183 100644
--- a/cmd/crc.c
+++ b/cmd/crc.c
@@ -7,6 +7,7 @@
 #include <stdlib.h>
 #include <sodium.h>
 #include <getopt.h>
+#include <pthread.h>
 #include "crc_util.h"
 #include "CRCLib.h"
 #include "crc.h"
@@ -65,11 +66,118 @@ int update_file_crc(unsigned char *addr, unsigned long offset , unsigned int crc
 	return 0;
 }
 
+static void random_window_bit_change(unsigned char *data, int width, int rounds, int color_range, size_t length) {
+	size_t random_num = 0;
+	for (int i = 0; i < rounds; i++) {
+		random_num = randombytes_uniform(length);
+		do {
+			random_num = randombytes_uniform(length);
+		} while((random_num % ((width * color_range) + 1)) == 0);
+
+		if(data[random_num] == 255) {
+			data[random_num]--;
+		} else {
+			data[random_num]++;
+		}
+	}
+	return;
+}
+
+static int verify_crc_chunks(unsigned char *data, size_t data_length, int crc_depth, unsigned int max_data_length) {
+	unsigned char* testing_chunk;
+	unsigned int crc_check = 0;
+	unsigned int test_data_length = 0;
+
+	for(int i = 0; i < crc_depth; i++) {
+		if((max_data_length * (i+1)) > data_length) {
+			test_data_length = (data_length - (max_data_length * i));
+			testing_chunk = calloc(test_data_length+4, sizeof(unsigned char));
+		} else {
+			test_data_length = max_data_length;
+			testing_chunk = calloc(test_data_length+4, sizeof(unsigned char));
+		}
+		testing_chunk[0] = 0x49;
+		testing_chunk[1] = 0x44;
+		testing_chunk[2] = 0x41;
+		testing_chunk[3] = 0x54;
+		for(int j = 0; j < test_data_length; j++) {
+			testing_chunk[j+4] = data[(max_data_length*i)+j];
+		}
+		crc_check = crc(testing_chunk, test_data_length);
+		
+		if(i == 2) {
+			printf("THIRD: %08X\n", crc_check);
+		} else if(i == 1) {
+			printf("SECOND: %08X\n", crc_check);
+		}
+		if ((crc_check >> (8*3)) != 10 ) {
+			free(testing_chunk);
+			return 1;
+		}
+	}
+	free(testing_chunk);
+	printf("FOUND: %08X\n", crc_check);
+	return 0;
+}
+
+static int crc_embed_data(unsigned char *data, unsigned int data_length, int bit_width, int color_range, unsigned int sliding_window) {
+	unsigned char *check_data;
+	size_t check_data_length = 0;
+
+	random_window_bit_change(data, bit_width, 3, color_range, sliding_window);
+
+	// Compressing data for test
+	zlib_compress_data(data, data_length, &check_data, &check_data_length);
+
+	int match_crc = verify_crc_chunks(check_data, check_data_length, 3, 8192);
+
+	if(match_crc == 0) {
+		free(check_data);
+		return 0;
+	}
+	free(check_data);
+	return 1;
+}
+
+void *random_data_change_thread_call(void *w) {
+	struct EMBED_THREAD_STRUCT *data = w;
+	unsigned char* temp_color_data = calloc(data->uncom_data_len, sizeof(unsigned char));
+	int searching = 1;
+	do {
+		// Creating temporary data set
+		memcpy(temp_color_data, data->data, data->uncom_data_len);
+
+		if(data->uncom_data_len > 800000) {
+			data->data_len = 150000;
+		} else {
+			data->data_len = data->uncom_data_len;
+		}
+		if(data->uncom_data_len > 16000) {
+			data->win_size = 9000;
+		} else {
+			data->win_size = data->uncom_data_len;
+		}
+
+		searching = crc_embed_data(temp_color_data, data->data_len, data->width, data->color_range, data->win_size);
+
+		if (searching == 0) {
+			pthread_mutex_lock(data->mutex_lock);
+			//pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
+			*data->searching = searching;
+			memcpy(data->data, temp_color_data, data->uncom_data_len);
+			//pthread_cancel(data->thread_id);
+			pthread_mutex_unlock(data->mutex_lock);
+		}
+
+	} while(*data->searching == 1);
+	free(temp_color_data);
+	return NULL;
+}
+
 void random_data_change(unsigned char *color_data, unsigned char *width, size_t length) {
 	int searching = 1;
-	size_t rounds = 0;
-	unsigned char* full_data;
-	int data_array_size = 0;
+	unsigned int sliding_window = 0;
+	unsigned int compress_data_length = 0;
 	// Needs to be turned into a variable
 	int color_range = 3;
 	// Union for width type cast
@@ -77,60 +185,27 @@ void random_data_change(unsigned char *color_data, unsigned char *width, size_t
 		uint32_t width_int;
 		unsigned char width_array[4];
 	}w;
-	// Temp data array for crc testing
-	unsigned char* temp_color_data = calloc(length, sizeof(unsigned char));
-
 	memcpy(w.width_array, width, 4);
 
-	do {
-		rounds++;
-		// Creating temporary data set
-		memcpy(temp_color_data, color_data, length);
-		// Generating random byte to change
-		size_t random_num = randombytes_uniform(100000);
-		//size_t random_num = randombytes_uniform(length);
-		// Checking for index break
-		if(random_num % ((be32toh(w.width_int) * color_range) + 1)) {
-			if(color_data[random_num] == 255) {
-				temp_color_data[random_num]--;
-			} else {
-				temp_color_data[random_num]++;
-			}
-			// Compressing data for test
-			unsigned char *check_data_buff = NULL;
-			size_t check_data_length = 0;
-			zlib_compress_data(temp_color_data, 50000, &check_data_buff, &check_data_length);
-			//zlib_compress_data(temp_color_data, length, &check_data_buff, &check_data_length);
+	// Temp data array for crc testing
+	//unsigned char* temp_color_data = calloc(length, sizeof(unsigned char));
 
-			if(check_data_length > 8192) {
-				data_array_size = 8192;
-				full_data = calloc(8196, sizeof(unsigned char));
-			} else {
-				data_array_size = check_data_length;
-				full_data = calloc(check_data_length+4, sizeof(unsigned char));
-			}
+	//int num_threads = 1;
+	struct EMBED_THREAD_STRUCT t_data;
+	t_data.searching = &searching;
+	t_data.data = color_data;
+	t_data.data_len = compress_data_length;
+	t_data.uncom_data_len = length;
+	t_data.width = be32toh(w.width_int);
+	t_data.color_range = color_range;
+	t_data.win_size = sliding_window;
+	pthread_t tid;
+	t_data.thread_id = tid;
+	for(int i = 0; i < 28; i++) {
+		pthread_create(&tid, NULL, random_data_change_thread_call, &t_data);
+	}
+	pthread_join(tid, NULL);
 
-			full_data[0] = 0x49;
-			full_data[1] = 0x44;
-			full_data[2] = 0x41;
-			full_data[3] = 0x54;
-			for(int i = 0; i < data_array_size; i++) {
-				full_data[i+4] = check_data_buff[i];
-			}
-			unsigned int temp_crc = crc(full_data, data_array_size);
-			printf("%08X\n", temp_crc);
-			if ((temp_crc >> (8*3)) == 10 ) {
-				printf("RAND Key: %zu\n", random_num);
-				printf("Found in %zu rounds!\n", rounds);
-				memcpy(color_data, temp_color_data, length);
-				searching = 0;
-			}
-			free(check_data_buff);
-		}
-	
-	} while(searching == 1);
-
-	free(temp_color_data);
 	return;
 }
 
@@ -200,7 +275,7 @@ int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, c
 		exit(EXIT_FAILURE);
 	}
 
-	size_t size = 1;
+	size_t size = 8;
 	size_t idat_byte_length = 0;
 	unsigned char* idat_data = calloc(size, sizeof(unsigned char));
 	for(size_t i = 0; i < total_idat(addr); i++) {
@@ -229,7 +304,7 @@ int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, c
 	// Start data testing
 	random_data_change(uncom_data_buff, png_file->png_start_data.file_width, uncom_data_size);
 	
-	return 0;
+	//return 0;
 	// Compress Data
 	unsigned char *com_data_buff;
 	size_t com_data_size = 0;
@@ -244,7 +319,7 @@ int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, c
 	}
 
 	// Build PNG File
-	//build_png_file(png_file, out_file_name);
+	build_png_file(png_file, out_file_name);
 
 	// Freeing used memory
 	free(uncom_data_buff);
diff --git a/include/crc_util.h b/include/crc_util.h
index 695146b..49189f0 100644
--- a/include/crc_util.h
+++ b/include/crc_util.h
@@ -33,6 +33,18 @@ struct PNG_FILE_STRUCT {
 	struct PNG_IDAT_FILE_STRUCT png_idat_data;
 };
 
+struct EMBED_THREAD_STRUCT {
+	pthread_mutex_t *mutex_lock;
+	pthread_t thread_id;
+	int *searching;
+	unsigned char *data;
+	unsigned int data_len;
+	size_t uncom_data_len;
+	int width;
+	int color_range;
+	unsigned int win_size;
+};
+
 extern const long png_signature[8];
 
 unsigned long check_header_length(unsigned char *addr, long offset);