Many digital systems need to provide cryptographic 1 capabilities. A large part of these devices is easily accessible 2 by the malicious user, and may be vulnerable to side channel 3 attacks such as power or electromagnetic analysis. From one 4 side, the designer has to protect the architecture with proven 5 countermeasures; on the other, the actual implementation must 6 be validated in order to prove the absence of undesired leakages.7In this paper, we present an implementation of two optimized 8 and proven masking schemes of order 3 and 7 for an embedded 9 software AES, and prove its robustness by showing the absence 10 of significant leakage in the nonlinear layer.