Cryptanalysis of a public-key cryptosystem based on generalized inverses of matrices

The theory of generalized inverses of matrices over finite fields has been proposed as a potential tool in cryptographic research for the past two years. Recently, Wu and Dawson (see IEE Proc., Comput. Digit. Tech., vol.145, no.5, p.321-6, 1998) proposed a public-key cryptosystem based on generalized inverses of matrices. In this letter, we show that the Wu-Dawson public-key cryptosystem can be broken by representing the ciphertext as a linear combination of rows according to the public key.