A

cipher text policy attribute based signcryption [CP-ABSC] scheme is proposed in [33] for cloud system for storing personal health record which gives access control, confidentiality and integrity of data.

The encryption system at key exchange center generates storage key K1 according to identification B1 to decrypt the

cipher text of T1 and perform integrity verification.

Decryption: Generate the key using similar technique which will generate the same key; depending on the received

cipher text length.

Plain Text A B C D E F G H I J K L M N O P Q R S T U V W X Y Z B C D E F G H I J K L M N O P Q R S T U V W X Y Z A

Cipher Text In this example, the plain text K is enciphered with the

cipher text L.

You digitally apply a key to plain text to get

cipher text.

3) There are not enough schemes designed for both multi-factor and

cipher text.

In this scheme the Network Abstraction Layer (NAL) units were extracted from stream and encrypted to make a

cipher text. By doing this computational complexity was reduced to some extent but compression efficiency was not improved.

They retrieved plain text bytes from

cipher text using single and double bias attacks.

Where [G.sub.c] is the

cipher text space and the [??] denotes the encrypted state transition function and [??] denotes the encrypted initial state.

G uses the key [K.sub.S-G] to encrypt M, and the obtained

cipher text is

Some mathematical operations are then performed to generate

cipher text from plain text with the use of key and initialized vector.

[6] such as using Gentry fully homomorphic encryption idea, put forward the key and the

cipher text with relatively small size of the solution, to improve the efficiency; Stehle and others optimized Gentry's scheme, put forward a fast fully homomorphic encryption scheme to reduce the computational complexity allowing the negligible probability decryption error on the weakened condition.