An efficient S-box with sound cryptographic features is of utmost significance for the development of strong cryptographic system. Designing cryptographically strong S-boxes is a key challenge. This paper put forward a method to synthesize an efficient 8×8 S-box. The method employed one-dimensional chaotic Logistic and Cubic maps in a way to modulate their normal system trajectories. The modulated trajectories are recorded and preprocessed, and one is dynamically selected to adjudge its suitability as an S-box cell. The proposed chaotic S-box design methodology is examined against various analytical tests such as bijectivity property, nonlinearity, strict avalanche criterion and equiprobable input/output XOR distribution. These statistical tests results ascertain the excellent performance of proposed method and prove it to be a promising choice as a nonlinear component in the design of a strong block cipher.