@spec new_keypair() :: %{public: ed25519_public(), secret: ed25519_secret()}

@spec sign(binary(), ed25519_secret()) :: binary()

@spec sign_detached(binary(), ed25519_secret()) :: binary()

@spec verify(binary(), ed25519_public()) :: {:ok, binary()} | {:error, term()}

@spec verify_detached(binary(), binary(), ed25519_public()) :: boolean()