International Science and Technology Journal

Digital signature is an advanced level of E-Government development stages which evaluate criterion for its maturity, in addition to being one of the most cryptography-based sciences, which is reliable in signing electronic documents such as contracts and agreements through encrypting the contents in order to verify reliability of signature. This study proposes a mechanism for employing advanced encryption standards AES as one of the symmetric encryption techniques in creating a digital signature on the official certificates issued by College of Technical Sciences - Derna, which is the algorithm of AES256 in producing a secret key for signing certificates digitally through a rapid and easy encryption mechanism. The main idea of this mechanism is to develop a two-pronged system, the documents are signed with encoded string generated through deletion, replacement and addition algorithms that are performed on data of certificate for generating one secret key used as a primary key in an intermediate. An encryption algorithm turns the primary key into a cipher text which is used to print a QR code on documents to save key data at first part. A WEB-Based Application with QR reader is acting as a second part of the system which was designed for retrieving data of decoded secret key. As a result of applying the stated encryption mechanism and experimenting the proposed system, the researchers have concluded that the system is capable for issuing and verifying certificates with high efficiency and reliability, which makes the possibility of intercepting certificate data and impersonating the signature owners almost impossible. Keywords: Digital Certificate - Electronic Signature - Symmetric Encryption – Decryption - QR Code - Authentication - AES - AES256.