In the case of cryptographic processing with the aid of an elliptic curve, parameters
of the elliptic curve are stored in a memory of a computer. These parameters are
each of substantial length. The elliptic curve is transformed in order to shorten
at least one parameter significantly in length and to ensure that the high security
level is unchanged in the process. One parameter is preferably shortened to 1,
-1, 2 or -2 with the aid of an algorithm, whereas the other parameters have a length
of several 100 bits. The shortening of even one parameter is clearly reflected
in the case of devices which have little memory space.