Non-linear chaos is a property of equations, cauterized by non-periodicity, the high sensitivity to initial conditions and his control parameters, ability to reciprocal synchronization and unpredictability. The deterministic nature of the chaotic system can be used to generate a pseudorandom sequence for digital ciphering algorithms. This work presents a pseudo-random bit generator (PRBG), based on the chaotic system, which can be used for generating keys in real encrypts application to ensure a secure transmission in real time. The proposed approach is applied for encryption image. The totality of the pixels of the host image are XORed with a generated key based on the Logistic map (LM). It is implemented in Xilinx System Generator (XSG). A PRBG architecture is considered.