Information is a commodity. Information has economic value and production of it incurs cost. Securing the information is posing a considerable challenge. The cryptographic technology plays a leading role in securing the owners right on produced information. A continuous development of new encryption systems are necessitated with the advancement in security and efficiency needs. Cryptanalytic studies have demonstrated the superior capability of recently developed Generalized Key Scheme Block Cipher (GKSBC) algorithm in terms of stability, execution time and encryption quality compared to standard security algorithms. This paper proposes to evaluate the enduring capacity of GKSBC to various cryptanalytic attacks viz., Brute – Force Attack, Differential Cryptanalysis, Integral Cryptanalysis, Linear Cryptanalysis and Rectangle attack. None of the traditional attacks are designed to decrypt GKSBC encryption as the use of key scheme is different in it and therefore robust to the conventional cryptanalytic attacks.