private void processEcCurve() {
    GenesisConfigOptions options = GenesisConfig.fromConfig(genesisConfig).getConfigOptions();
    Optional<String> ecCurve = options.getEcCurve();

    if (ecCurve.isEmpty()) {
      SignatureAlgorithmFactory.setInstance(SignatureAlgorithmType.createDefault());
      return;
    }

    try {
      SignatureAlgorithmFactory.setInstance(SignatureAlgorithmType.create(ecCurve.get()));
    } catch (IllegalArgumentException e) {
      throw new IllegalArgumentException(
          "Invalid parameter for ecCurve in genesis config: " + e.getMessage());
    }
  }
Sets the selected signature algorithm instance in SignatureAlgorithmFactory.
app/src/main/java/org/hyperledger/besu/cli/subcommands/operator/GenerateBlockchainConfig.java