The invention provides a method for ciphering and transmitting data, to be used by a communication device being arranged to transmit data through a first data port (241, 2002) according to a first transmission protocol, and to form ciphered exploiting a ciphering algorithm being fed with a first set of ciphering parameters, comprising a ciphering parameter CP5; said device being further arranged to transmit data through a second data port (242, 2003) according to an alternative transmission protocol, said method comprising the steps of: defining an alternative ciphering parameter, ACP, having a bit length equal to the bit length of CP5, forming a second set of ciphering parameters by substituting said CP5 with said ACP in said first set of ciphering parameters, forming ciphered data by subjecting the data to said ciphering algorithm being fed with said second set of ciphering parameters, transmitting said ciphered data through said second data port (242, 2003). The invention also provides a software program and communication devices realising said method.