A data encryption model based on logistic map is studied and multiple chaotic dynamical systems were implemented to improve by addressing the issues related to use of logistic map. Use of different chaotic systems other than logistic map, provides us to vary control parameters to a larger extent, hence enabling to overcome the limitations of logistic map without compromising security of data. Further, a large range of control parameters were provided to make system more key dependent. The measure of degree of complexity in the cipher was examined for different chaotic dynamical systems. The proposed method eliminates the issues related to distribution of randomly generated data by using Lozi, Henon, Tent and Bernoulli maps for given values of control parameters.