Stream Ciphers

• In Stream Cipher, encryption & decryption are done on one symbol (such as a character or a bit) at a time.

$P=P_1,P_2,P_3, …..$ $C=C_1C_2C_3…$ $K=(K_1, K_2, K_3 …)$

$\phantom{P=}\downarrow$ $\phantom{_1,P_2,P_3, ….. ;...;}\downarrow$ $\phantom{_1,P_2,P_3fgfdghfd}\downarrow$

$C_1=E_{K_1}(P_1)$ $\phantom{asdsa}$$C_2=E_{K_2}(P_2)$ $\phantom{asdsa}$ $C_3=E_{K_3}(P_3)$

The figure below gives the idea behind a stream cipher. Character …