摘要：Rijndael-The AES is 128-bit block cipher based on an elegant algebraic structure over F28. This cipher employs a simple approach to its substitution, permutation (SP) operations. We take a close look on the Key Expansion Mechanism of Rijndael - The AES. This study highlights on the presence of the cascading effect in its key expansion mechanism. Thus, lowering the brute-force key guess attack by a factor of 231. Hence, for the key size of 128 bits the key diversity is 297 instead of 2128.
