Improved Rabin's scheme with high efficiency
Lein Harn, T. Kiesler · Electronics Letters · 1989
The letter proposes a modified public-key cryptosystem based on the Rabin scheme. It can provide simultaneously both private encryption and digital signatures for network users. In the cases where it provides only encryption or only digital signatures, the scheme provides that the bit ratio between plaintext and ciphertext is 1:1 , i.e. equivalent to that of the RSA scheme.