Two new efficient cryptosystems based on Rabin´s scheme: alternatives to RSA cryptosystem

Proposes two distinct cryptosystems based on Rabin´s scheme. The first incorporates coding theory and provides encryption only. The second provides simultaneously both private encryption and digital signature for network users. In the cases where the second scheme provides only encryption or only digital signature, the scheme provides that the bit ratio between plaintext and ciphertext is 1:1, i.e. equivalent to that of the RSA scheme