) throws IOException {
        List<PGPPublicKeyRing> existingRings = loadExistingKeyRing(existingKeyring);
        PGPPublicKeyRingListBuilder builder = new PGPPublicKeyRingListBuilder();
        for (String publicKey : publicKeys) {
            if (publicKey.length() <= 16) {
                publicKeyService.findByLongId(new BigInteger(publicKey, 16).longValue(), builder);