The need for fast but secure cryptographic systems is growing bigger. Therefore, dedicated hardware for cryptography is becoming a key issue for designers. With the spread of reconfigurable hardware such as FPGAs, embedded cryptographic hardware became cost-effective. Nevertheless, it is worthy to note that nowadays, even hardwired cryptographic algorithms are not safe. Attacks based on power consumption and electromagnetic Analysis, such as SPA, DPA and EMA have been successfully used to retrieve secret information stored in cryptographic devices. Besides performance in terms of area and throughput, designer of embedded cryptographic hardware must worry about the leakage of their implementations. This paper deals with the leakage that occurs in the SW computation of AES on platforms equipepd with a cache memory through the miss events, which may allow to infer the secret key.