Witriyono, Harry, and Sandhy Fernandez. “Enkripsi Base 64, Hashing SHA1 Dan MD5 Pada QR Code Presensi Kuliah”. JSAI (Journal Scientific and Applied Informatics), vol. 4, no. 2, July 2021, pp. 263-72, doi:10.36085/jsai.v4i2.1680.