Design And Implementation Of Pseudo-random Number Generator Based On AES

Random numbers have been widely used in various fields of computer science,especially in the field of cryptography. The randomness of random numbers directly affects the security of data encryption,digital signature, authentication,and so on. The impact of random numbers on the information system is particularly significant when they are used as cryptographic keys. In reality, most of the random numbers used in computer systems are generated from the pseudo-random number generators which are usually implemented by some deterministic algorithms with input information of good randomness.Due to the importance of pseudo-random number generators,this thesis mainly studies the design and implementation of pseudo-random number generator based on advanced data encryption standard AES, and discusses the applications of the designed pseudo-random number generator.Firstly, a pseudo-random number generator is designed using the CBC operation mode of AES encryption algorithm as the key tool. The pseudo-random number generator uses the millisecond time,nanosecond time and CPU's usage of the current system as the random input information. These three kinds of information are divided into plaintext, cipher key and initial vector of the encryption algorithm. The number of plaintext blocks is determined according to the number and range of the output random numbers required. Each plaintext block is encrypted by AES to generate the ciphertext, and the resulted ciphertext is cut and transformed to output a specific number of pseudo-random numbers within .the predetermined range.Secondly, the designed pseudo-random number generator based on AES is implemented, and its performance is analyzed. In performance analysis, the time consumption test, NIST SP800-22 standard test, frequency test and numerical distribution test are mainly executed. The statistical analysis of a large number of experimental results reveal that the proposed pseudo-random number generator shows a good stability of performance, and its output possesses good randomness,independence, and uniformity.Finally, using the design principle and idea of the pseudo-random number generator based on AES,a lottery system and a key generation system are designed and implemented. The experimental results show that the two application systems are stable and can meet the needs of practical randomness requirements of lottery and key generation.