The chaotic generation is of great interest in Encryption/Decryption process. It is increasingly applied in Key generation that is used for encryption/decryption of plain text data before transmission to the required destination. The chaos pattern is first generated as phenomena of nonlinear unstable analog circuit. The problem is limited word length size of the key generated (small key space) which has low brittle force and it is susceptible to key estimation and as a result weak security. In this paper a new algorithm of adaptive digital chaotic generator is proposed and keys blocks of different length are produced. The randomness of the generated key sequences is tested and evaluated for different initial conditions and different learning periods. The results are encouraged.