private static ProtoParametersSerialization serializeParameters(AesSivParameters parameters)
      throws GeneralSecurityException {
    return ProtoParametersSerialization.create(
        KeyTemplate.newBuilder()
            .setTypeUrl(TYPE_URL)
            .setValue(
                com.google.crypto.tink.proto.AesSivKeyFormat.newBuilder()
                    .setKeySize(parameters.getKeySizeBytes())
                    .build()
                    .toByteString())
            .setOutputPrefixType(toProtoOutputPrefixType(parameters.getVariant()))
            .build());
  }
Parse LEGACY prefix to CRUNCHY, since they act the same for this type of key
java_src/src/main/java/com/google/crypto/tink/daead/internal/AesSivProtoSerialization.java