The aim of this report is to investigate an adaptive synchronization (AS) for the general class of complex hyperchaotic models with unknown parameters and a new algorithm to achieve this type of synchronization is proposed. Owing to the intricacy behavior of hyperchaotic models that could be effective in secure communications, the special control based on adaptive laws of parameters is constructed analytically, and the corresponding simulated results are performed to validate the algorithm's accuracy. The complex Rabinovich model is utilized as an enticing example to examine the proposed synchronization technique. A strategy for secure communication improving the overall cryptosystem is proposed; the scheme is designed to split the message and insert some bit of information signal into the modulation parameters and the other bit into the transmitter system's states, making decryption by intruders more difficult. Meanwhile, adaptive techniques and a decryption function on the receiver side can accurately retrieve the message. Different types of encoded messages are examined for testing the robustness of the proposed scheme (e.g., text and gray images with diverse scales of white Gaussian noise). (C) 2021 Elsevier B.V. All rights reserved.