Performing Elliptic Curve Operations
260 RSA BSAFE Crypto-C Developer’s Guide
Performing Elliptic Curve Operations
Elliptic curve cryptosystems can be used for a number of public-key operations.
Crypto-C supports the following elliptic curve features:
•Generation of elliptic curve parameters
•Elliptic curve key pair generation
•Elliptic Curve Signature Schemes (ECDSA)
•Elliptic Curve Authenticated Encryption Scheme (ECAES)
•Elliptic Curve Diffie-Hellman key agreement (ECDH)
Crypto-C also allows you to generate precomputed acceleration tables to speed up
certain elliptic curve operations.
For a description of elliptic curve parameters and algorithms, see “Elliptic Curve
Cryptography” on page 65.

Generating Elliptic Curve Parameters

Before you can perform any elliptic curve operations, you must create the parameters
for the curve that you will be using. Once you have generated elliptic curve
parameters, you can use the parameters to: generate a key pair, to create an
acceleration table, or to perform Elliptic Curve Diffie-Hellman (ECDH) key
agreement. The same elliptic curve parameters can be used for multiple operations.
See “Elliptic Curve Parameters” on page 66 for more information.
You need to make some choices about the kind of elliptic curve you want to use. You
need to choose what to use for a base field: an odd prime finite field or a field of even
characteristic. If you choose a field of even characteristic, you also have to choose
what type of basis you want to use. You also have to choose the number of bits that
you want for the length of an element in the field.
For this example, you will use an odd prime field for the base field. The example in
this section corresponds to the file ecparam.c.
Step 1: Creating an Algorithm Object
You need to create two algorithm objects. The first,
paramGenObj
, is initialized by the
programmer prior to the parameter generation operation; it is used to hold
information necessary to generate parameters.