The relationship between structure of the key space and hardness of the McEliece–Sidelnikov Public Key Cryptosystem

In the paper a number of the problems connected with the hardness of original McEliece PKC and McEliece–Sidelnikov PKC with restrictions on key space is considered. The polynomial equivalence of breaking problems for McEliece PKC and McEliece–Sidelnikov PKC with restrictions on the key space is proved.