A Chosen Text Attack on the RSA Crytisystem and Some Discrete Logarithm Schemes

A new attack on the RSA crytosystem is presented. This attack assumes less than previous chosen ciphertext attacks, since the cryptanalyst has to obtain the plaintext versions of some carefully chosen ciphertexts only once, and can than proceed to decrypt futher ciphertexts without further recourse to the authorized user's decrypting facility.