THE ELECTRONIC DOCUMENT MANAGEMENT AND ELECTRONIC INFORMATION SENDING AND RECEIVING MAKE UP THE LARGE PART OF TODAY'S ACTIVITIES IN THE WORLD. THE USE OF COMPUTER-BASED INFORMATION IS SIGNIFICANTLY GROWING THROUGHOUT THE WORLD. THE DIGITAL SIGNATURE IS ONE OF THE TECHNOLOGIES WHICH HAVE INCREASED THE CONFIDENCE. THISENCRYPTION-BASED TECHNIQUE HAS RECOGNIZED THE ELECTRONIC INFORMATION, SO THAT THE DOCUMENT CREATOR'S IDENTITY AND HIS INFORMATION COMPREHENSIVENESS CAN BE REVIEWED AND CONTROLLED; AND THE TRADITIONAL METHODS OF PHYSICAL MARK BY SEAL OR SIGNATURE (FOR BUSINESS AND LEGAL PURPOSES) ARE UNUSABLE DUE TO THE NON-PHYSICAL STRUCTURE (DATA CARRIER). THIS STUDY PROPOSES A DIGITAL SIGNATURE SCHEME BASED ON VALID RSA ALGORITHM. RSA ALGORITHM IS A PUBLIC KEY ENCRYPTION SYSTEM WHICH PROVIDES BOTH ENCRYPTION AND DIGITAL SIGNATURE SERVICES. THIS PROPOSAL SCHEME HAS THE FEATURES NAMELY THE MESSAGE CONFIDENTIALITY, RELIABILITY, VALIDITY AND INTEGRITY, INCONTROVERTIBILITY, AND AUTHENTICATION. IN THIS SCHEME, BOTH ENCRYPTION AND AUTHENTICATION ARE PERFORMED WITHOUT SHARING THE PRIVATE KEYS. EACH PERSON PERFORMS DESIRED OPERATION THROUGH HIS PRIVATE KEY OR THE OPPOSITE PARTY'S PUBLIC KEY. ANYONE CAN SEND AN ENCRYPTED MESSAGE OR REVIEW A SIGNED MESSAGE. HOWEVER, ONLY THE PRIVATE KEY HOLDER CAN DECRYPT OR SIGN A MESSAGE. DUE TO THE EFFECTIVENESS OF THIS SCHEME IN TERMS OF RUNNING SPEED AND DURATION AND THE EXISTENCE OF SECURITY PARAMETERS, IT CAN BE USED ON A VARIETY OF SECURITY SYSTEMS SUCH AS SMART CARDS, WEB SERVER, BANKING SYSTEMS, AND SO ON.