diff --git a/set1/Makefile b/set1/Makefile
index cc27bd7..e01c43e 100644
--- a/set1/Makefile
+++ b/set1/Makefile
@@ -20,7 +20,6 @@ EXT_INCLUDES = -Iaes-libs/tiny-AES-c
 #EXT_LIBS     = -Laes-libs/tiny-AES-c
 #LDLIBS       = -laes
 
-#%: $(SRC_DIR)/%.c
 %: $(SRC_DIR)/%.c
 	$(CC) $(CFLAGS) -o $(OUT_DIR)/$@ $<
 
diff --git a/set1/src/ch3-brute-force.c b/set1/src/ch3-brute-force.c
new file mode 100644
index 0000000..ed75679
--- /dev/null
+++ b/set1/src/ch3-brute-force.c
@@ -0,0 +1,28 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main()
+{
+	uint8_t i = 0;
+	size_t k;
+	int8_t ciphertext[] = "\x1b\x37\x37\x33\x31\x36\x3f\x78\x15\x1b\x7f\x2b"
+	                      "\x78\x34\x31\x33\x3d\x78\x39\x78\x28\x37\x2d\x36"
+	                      "\x3c\x78\x37\x3e\x78\x3a\x39\x3b\x37\x36";
+	int8_t attempt[sizeof(ciphertext) - 1];
+
+	do {
+		printf("i = %d\n", i);
+		for (k = 0; k < sizeof(attempt); ++k) {
+			attempt[k] = ciphertext[k] ^ i;
+		}
+		for (k = 0; k < sizeof(attempt); ++k) {
+			putchar(attempt[k]);
+		}
+		putchar('\n');
+		++i;
+	} while (i < 255);
+
+	return EXIT_SUCCESS;
+}
+