Abstract: Rainbow is a digital signature scheme. It is based on multivariate polynomials, which belongs to multivariate public key cryptography. Compared with the existing signature schemes, e.g. rivest-shamir-adleman (RSA) and ellipse curve cryptography (ECC), Rainbow can resist quantum computer attacks, which is a candidate of the signature schemes of the next generation. According to the importance of Rainbow, in this paper, we present techniques to exploit differential power analysis (DPA) and fault analysis attacks for analyzing the effectiveness of side channel attacks on Rainbow signature. We implement a naive Rainbow scheme on hardware and propose a successful side channel attack on the implementation. Experimental results show that our attack successfully obtains all the pieces from the private keys of the Rainbow scheme and they clearly demonstrate that we need to protect Rainbow against side channel attacks.