The Design Of Safety Digital Password Locks Based On Fingerprint Identification Technology

Fingerprint identification technology is an effective means of identity authentication.Fingerprint identification technology has been deep into all areas,all sorts of fingerprint lock products emerge in endlessly,at present,the fingerprint lock product safety sets of serious threat by false fingerprints and fingerprint,fingerprint is copied everywhere.If the fingerprint is leaked and has been successfully copied,the fingerprint lock will be useless.Electronic combination lock,because the password is easily leaked or stolen,it’s security is extremely low.In view of the security problems of fingerprint lock and electronic combination lock,this thesis puts forward a design method of safe combination lock which based on fingerprint identification technology and dynamic digital password technology,Analyses the traditional digital encryption algorithm,and puts forward the improved algorithm,improves the security of the system,the research contents are as follows:First,the fingerprint identification module and the digital password are combined to design a security password lock with double identification of fingerprint identification and digital code.Safety locks hardware mainly consists of two parts:safety lock controller and password generator,the password generator uses the XOR dynamic password generation method based on the time synchronization,safety lock controller is used in the dynamic password and fingerprint matching are control of unlocking the case of success.The safety lock controller consists of microprocessor,keyboard unit,LCD display,fingerprint module,alarm circuit,power supply circuit,a storage unit,USB serial circuit,clock circuit and actuator etc.The password generator is composed of a microprocessor,a keyboard unit,a clock circuit and a liquid crystal display.Safety locks in administrator mode can add,delete,fingerprint lock,modify the emergency key etc;in the lock mode,wait for input dynamic password,if the password is correct,then,waiting for a fingerprint and access with fingerprint comparison,the success ratio will unlock.Password input 3 times are not correct then start alarm circuit alarm.Second,the study of fingerprint image acquisition,fingerprint image segmentation,fingerprint image enhancement,fingerprint image value of two basic principle and refined,fingerprint feature extraction and fingerprint matching,advantages and disadvantages of different algorithms to compare the fingerprint processing process,according to the design requirements of safety and performance,determine the final selection of fingerprint module.Third,in-depth study of digital encryption algorithm,a time synchronization based on improved digital encryption algorithm.Selection of high precision I2C real-time clock chip DS3231,read the chip’s time information which is used as a variable factor,combining can modify the key generation of dynamic password in the modified XOR encryption algorithm,increasing the difficulty of cracking and improve the safety of cipher lock.Actual test results and operation show that the design based on fingerprint identification of the safety of the combination lock can achieve dynamic password generation,fingerprint various functions such as add,delete,comparing,meet the requirement of security design.