Cryptanalysis of Xinmei digital signature scheme

In 1990, Xinmei proposed a digital signature scheme based on error-correcting codes. It was claimed that the security of the signature scheme relies on the difficulty of factoring large matrices and the properties of error-correcting codes. Now it is shown that the private key in the Xinmei scheme can be obtained directly from the public key. As a result this scheme is insecure. In conclusion a modification proposed by Harn and Wang (see ibid., vol.28, no.2, p.157-9, 1992) is briefly discussed.