Encryption plays a crucial role in securing multi-user systems, especially in environments where data is shared among multiple parties. Various approaches have been developed to enhance security, manage keys, and ensure data integrity in these systems. This paper introduces a security system for a multiuser system that was suggested in order to identify the users of the system. That is why most security systems only utilize one algorithm to code the system or identify its users. According to the research, the user’s biometric will be combined with the system’s algorithms to create a Digital Signature that will allow us to identify the system’s user. This work presents a new approach in image encryption by combining the merits of RSA and Chaotic maps, namely Lorenz and Logistic. First the Iris biometric provided the initial value for the chaotic Algorithm. Where biometric is encrypted by RSA and the plain image encrypted by chaotic, after these processes the two encryption images are vertically concatenated. Finally, the diffusion process is implemented using the Zig-Zag method. The most important conclusions that were reached the initial value adaptive with each user to the system. The digital signature of each user is used in addition signature for the system Finally the security analysis results has shown that the proposed algorithm has strong security and resistance to differential and statistical attacks, with the values for the NPCR of the image equalling 99.605, that for UACI equalling 35.805, and the capability of de-correlating the adjacent pixels of the cipher image, which resulted in a near-zero correlation coefficient.