Method and System for Protecting Data Requiring User's Authentication at Computer

PURPOSE: A contents securing method and a system thereof are provided to safely secure certificates used in an electronic commerce, and softwares or sound files sold over the internet so that it can prevent an illegal copy of the certificates. CONSTITUTION: The method comprises steps of storing a directory data file and a secret code input limit data file on a certificate document, set by a certificate document provider, at a buffer(S100), storing a simple usage number and copy number management file on the certificate document at a buffer(S110), detecting access request to the certificate document file stored in a directory registered in a management data file by monitoring all the accesses to all the files(S120), determining if an access request is an access to a certificate process file or a simple access(S130), checking if a continuous certification failure number is over a limit number in the case that the access request is an access to a certificate process file, and checking if the access request is a simple usage or a write/copy in the case that the access request is a simple access.