<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def set_terminal_key(self, encrypted_key):
 """ Change the terminal key. The encrypted_key is a hex string. encrypted_key is expected to be encrypted under master key """

        if encrypted_key:
            try:
                new_key = bytes.fromhex(encrypted_key)
                if len(self.terminal_key) != len(new_key):
                    # The keys must have equal length
                    return False

                self.terminal_key = self.tmk_cipher.decrypt(new_key)
                self.store_terminal_key(raw2str(self.terminal_key))

                self.tpk_cipher = DES3.new(self.terminal_key, DES3.MODE_ECB)
                self.print_keys()
                return True

            except ValueError:
                return False

        return False