onstructing stream cipher algorithm in fast and comfortable way is an important requirement for those people specialists in designing stream cipher algorithms to secure their information. The proposed package provides the designer the ability to construct stream algorithm in two ways, the first is building stream algorithm visually by providing a graphical interface and a number of stream cipher algorithm components, and the ability to make connections among selected components to produce the

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... y stream of the any desired length. The second way is constructing stream cipher through enter the C# programming code of the stream algorithm, the package executes the entered C# code and produce output as sequence of binary digits that represent the keystream, also the package will display messages to the designer if the entered code has any syntax errors. The parallel programming is used in construct the proposed package to speed up the operation of generating the key stream that produced in the visual way. I. INTRODUCTION As we enter the information age and the emergence of the means of digital transmission and storage of data in digital form, there was a need to develop ways to protect information from theft. [1] . Cryptography includes design and analysis a mathematical technique that provide a secure connection in the presence of a third party that seeking to disclosure of transmitted or stored information [2] . Stream cipher algorithm is one ways that used to encrypt the information and convert it into another form. Stream cipher has number of features, it is fast, and considered efficient in hardware because it is not required expensive hardware circuit. Therefore, the construction and design of stream cipher algorithm in fast and comfortable manner is an important need for those people who specialize in building stream cipher algorithm to protect their information from theft [3] . Encryption algorithm can be classified into two types, the first type is symmetric encryption, in this type used one private key that shared between the communication parties (the sender and the recipient). The second type is asymmetric encryption, in this type used two keys, the first public and open for everyone, and the second is kept secret, and in this type one key cannot be inferred from the other keys [4] . Asymmetric encryption is slow because it's based on mathematical theories, which is impractical in applications that require live and direct processing. In symmetric encryption, there are two types of algorithms, block algorithm and stream algorithm, in Block encryption algorithm the plaintext dividing into blocks of bits. Famous Block algorithms are AES and DES [5] . Stream cipher is developed as a solution to the problems of encryption one-time pad system. In one-time pad the key must be completely random and its length is equal to the length of the message to be encrypted and uses one time, because of the impracticability of one-time pad system so stream encryption system consider acceptable solution to these problems. In the stream cipher algorithm, pseudo-random key is generated using one of pseudo-random generator [6] . Encryption in stream cipher is done by dividing the clear text into bits and then every bit is encrypted individually. Stream algorithm relies entirely on security of pseudorandom key stream. To design stream algorithm, the designer can use several components and methods, the LFSR is most popular components used in the constructing of stream algorithm [7] .