private static OutputPrefixType toProtoOutputPrefixType(AesSivParameters.Variant variant)
      throws GeneralSecurityException {
    if (variantsToOutputPrefixMap.containsKey(variant)) {
      return variantsToOutputPrefixMap.get(variant);
    }
    throw new GeneralSecurityException("Unable to serialize variant: " + variant);
  }
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