In this paper, the authors present a method to hide information in JPEG standard image format. The proposed method is based on the Z2-module that will hide secret information in the low and medium frequency zone from quantized DCT coefficients. When the sender use the hiding confidential information schema: Each block after DCT transformation will be transformed into binary bits in orders and divided into modules
From each module, the schema will change maximum 3 bits to hide secret 7 bits. The receiver can extract information from images containing secret data by using the information to extract schema. the method is easy to process and works effectively with the ability to hide information, size and quality of image included hiding information and especially with the safety of hidden confidential information.