Data transferred in an electronic way is vulnerable to attacks. With an aim to protect data for secure communication, a new Hybrid non pipelined Advanced Encryption Standard (AES) algorithm based on traditional AES algorithm with enhanced security features is proposed in this work. Abysmal analysis of the AES algorithm implies that the security of AES lies in the S-box operations. This paper presents a new approach for generating S-box values (modified S-box) and initial key required for encryption/encryption (improved key generation) using PN Sequence Generator. The AES algorithm with proposed modifications shows significant improvement in the encryption quality as compared to traditional AES algorithm. The traditional AES algorithm equipped with proposed novel modified S-box technique and improved key generation technique gives an avalanche effect of 60% making it invulnerable to attacks. The proposed design is synthesized on various Field Programmable Gate Array (FPGA) devices and compared to the existing designs resulting in significant improvement in throughput. The proposed design is implemented on Spartan6 FPGA device.