diff --git a/include/common/f8.h b/include/common/f8.h
new file mode 100644
index 0000000..df3ef81
--- /dev/null
+++ b/include/common/f8.h
@@ -0,0 +1,37 @@
+/*-----------------------------------------------
+ * * f8.h
+ * *---------------------------------------------
+ */
+
+/* The code has been referred from
+ * 1. https://www.gsma.com/aboutus/wp-content/uploads/2014/12/uea2uia2d1v21.pdf
+ * 2. https://www.gsma.com/aboutus/wp-content/uploads/2014/12/snow3gspec.pdf
+ */
+
+
+#ifndef F8_H_
+#define F8_H_
+#include "snow_3g.h"
+
+
+/* f8.
+ * Input key: 128 bit Confidentiality Key.
+ * Input count:32-bit Count, Frame dependent input.
+ * Input bearer: 5-bit Bearer identity (in the LSB side).
+ * Input dir:1 bit, direction of transmission.
+ * Input data: length number of bits, input bit stream.
+ * Input length: 32 bit Length, i.e., the number of bits to be encrypted or
+ * decrypted.
+ * Output data: Output bit stream. Assumes data is suitably memory
+ * allocated.
+ * Encrypts/decrypts blocks of data between 1 and 2^32 bits in length as
+ * defined in Section 3 of
+ * https://www.gsma.com/aboutus/wp-content/uploads/2014/12/snow3gspec.pdf
+ * specs document
+*/
+
+
+void f8( u8 *key, u32 count, u32 bearer, u32 dir, u8 *data, u32 length );
+
+
+#endif