node [style = rounded, shape = rect] ED [label="y=edgeDetection(b bits)"]
node [style = rounded, shape = rect] decrypt [label="message=decryption(m)"]
node [style = rounded, shape = rect] ED [label="y=edgeDetection(b bits)"]
node [style = rounded, shape = rect] decrypt [label="message=decryption(m)"]