Securing information has been the most significant process for communication and data store. Orderly to secure information such as data authentication,  data integrity, and confidentiality must be verified based on algorithms of cryptography. Where, the most important part of any encryption algorithms is the key which specifies if the system is strong enough or not. The proposal of this paper is a new method to generate keys based on two kinds of chaos theory in order to improve the security of cryptographic algorithms. The base of this proposal is to investigate a new method for generating random numbers by using the 3D Lorenz system and 2D Henon map. The newly generated keys have successfully passed the National Institute of Standards and Technology (NIST) statistical test suite