The Fountain_codes-based Encryption And Decryption Algorithm Research

At current information age,information have run through our whole society,economy and culture and so on,which are closely connected to our benefit,so informational security have been brought to our attention,one of which is how to ensure the problems of informational security that will be currently solved.But traditional symmetric encryption algorithms are carrying out encryption operations for large files to ensure informational security,for example,the security of DES is lower so that information can be broken.Internet datum are transmitted to receivers by fountain code,in order to ensure the reliability of data,fountain code adopts randomized coding.Therefore,the paper uses the randomized coding theory of fountain code to apply encryption algorithm to improve the security of encryption algorithm,and proposed the Fountain_codes-based Encryption Algorithm(FEA),which is symmetric encryption algorithm.The keys of FEA inherit the randomize code character of Fountain codes,and carry out randomized cycle-shift and iteration-xor operation for plaintext to produce encryption-datum,which will be carried out disturbing xor operation by encryption-key to produce ciphertext.The research has been shown that the key-lengths of FEA are variable and expansible,and randomized cycle-shift,iteration-xor and disturbing xor operations enhance the complexity of encryption,and it carries out n rounds of iteration encryption algorithm,therefore,the security of FEA is higher.The key-lengths of FEA are variable and expansible,with the increasing of key-lengths,its entropy will become bigger,so the breaking of key also become more difficult and information will become securer.The key-lengths of FEA are variable,however,the key-lengths of traditional encryption algorithm are constant.Users want to set as its key-lengths according to the important degree of information,in other words,some important information is set as Longer key or some unimportant information is set as shorter key,therefore,FEA are more suitable for users to manage information and key than traditional encryption algorithm.The experiment have beenproved that large datum are carried out the encryption algorithm of FEA by form to extremely decrease the calculated amount of encryption algorithm and encryption time,and the encryption time of FEA are less than the encryption time of traditional encryption,so the encryption efficiency of FEA are higher than the encryption efficiency of traditional encryption to meet the requirement of users for large files.The paper is that the method of exhaustion and supercomputer decipher the keys of encryption algorithm,the key-lengths of FEA are variable(extensible),therefore,with increasing of key-length,the key breaking-time of encryption algorithm will be increasing,and informational security also will be increasing.