A method for generating a secret or a key in a network, the network including at least one first and one second member and a transmission channel between at least the first and the second members. The first and second members being able to place at least one first value and one second value on the transmission channel. The first member causes a first member value sequence and the second member causes a second member value sequence to be transmitted over the transmission channel largely synchronously with each other. The first member and the second member generate a shared secret or a shared key on the basis of information about the first member value sequence and the second member value sequence and on the basis of an overlap value sequence resulting from the overlap of the first member value sequence with the second member value sequence on the transmission channel.