Cipher block chaining (CBC) is a method of activity for a block cipher. The sequence of bits are encrypted as a single unit, with a cipher key applied to the whole block. Cipher block chaining utilizes an initialization vector (IV). Associations and individuals can securely encrypt and decrypt large amounts of plaintext. Cipher block chaining is one of the most used methods for encrypting large messages,by utilizing the initialization vector along with a single encryption key. CBC can encrypt large plaintext inputs yet at a slower pace than some parallel encryption algorithms, for a more secure electronic codebook (ECB) successory.