**3. Protocol of implementation of cross-layer security scheme**

The new scheme is implemented at the application and physical layers. The detail operations of the application and physical layers at the source and destination are as follows:

	- Application layer:

a. Traditional RSA encryption

	- a. Step 1: Residue number system (RNS) converts the message points into residues based on the moduli set;

b.Step 2: RNS-based RSA ciphertext is converted into different levels of decomposition using subband coding; c. Step 3: Symmetric encryption using Convolutional cryptosystem;

At the destination, the entire process is reversed starting with convolutional decoding at the physical layer and ending with RSA decryption at the application layer.
