I am trying to encrypt and decrypt data using AES/GCM/NoPadding. I installed the JCE Unlimited Strength Policy Files and ran the (simple minded) benchmark below. I've done the same using OpenSSL and was able to achieve more than 1 GB/s encryption and decryption on my PC.
With the benchmark below I'm only able to get 3 MB/s encryption and decryption using Java 8 on the same PC. Any idea what I am doing wrong?
public static void main(String[] args) throws Exception {
final byte[] data = new byte[64 * 1024];
final byte[] encrypted = new byte[64 * 1024];
final byte[] key = new byte[32];
final byte[] iv = new byte[12];
final Random random = new Random(1);
random.nextBytes(data);
random.nextBytes(key);
random.nextBytes(iv);
System.out.println("Benchmarking AES-256 GCM encryption for 10 seconds");
long javaEncryptInputBytes = 0;
long javaEncryptStartTime = System.currentTimeMillis();
final Cipher javaAES256 = Cipher.getInstance("AES/GCM/NoPadding");
byte[] tag = new byte[16];
long encryptInitTime = 0L;
long encryptUpdate1Time = 0L;
long encryptDoFinalTime = 0L;
while (System.currentTimeMillis() - javaEncryptStartTime < 10000) {
random.nextBytes(iv);
long n1 = System.nanoTime();
javaAES256.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"), new GCMParameterSpec(16 * Byte.SIZE, iv));
long n2 = System.nanoTime();
javaAES256.update(data, 0, data.length, encrypted, 0);
long n3 = System.nanoTime();
javaAES256.doFinal(tag, 0);
long n4 = System.nanoTime();
javaEncryptInputBytes += data.length;
encryptInitTime = n2 - n1;
encryptUpdate1Time = n3 - n2;
encryptDoFinalTime = n4 - n3;
}
long javaEncryptEndTime = System.currentTimeMillis();
System.out.println("Time init (ns): " + encryptInitTime);
System.out.println("Time update (ns): " + encryptUpdate1Time);
System.out.println("Time do final (ns): " + encryptDoFinalTime);
System.out.println("Java calculated at " + (javaEncryptInputBytes / 1024 / 1024 / ((javaEncryptEndTime - javaEncryptStartTime) / 1000)) + " MB/s");
System.out.println("Benchmarking AES-256 GCM decryption for 10 seconds");
long javaDecryptInputBytes = 0;
long javaDecryptStartTime = System.currentTimeMillis();
final GCMParameterSpec gcmParameterSpec = new GCMParameterSpec(16 * Byte.SIZE, iv);
final SecretKeySpec keySpec = new SecretKeySpec(key, "AES");
long decryptInitTime = 0L;
long decryptUpdate1Time = 0L;
long decryptUpdate2Time = 0L;
long decryptDoFinalTime = 0L;
while (System.currentTimeMillis() - javaDecryptStartTime < 10000) {
long n1 = System.nanoTime();
javaAES256.init(Cipher.DECRYPT_MODE, keySpec, gcmParameterSpec);
long n2 = System.nanoTime();
int offset = javaAES256.update(encrypted, 0, encrypted.length, data, 0);
long n3 = System.nanoTime();
javaAES256.update(tag, 0, tag.length, data, offset);
long n4 = System.nanoTime();
javaAES256.doFinal(data, offset);
long n5 = System.nanoTime();
javaDecryptInputBytes += data.length;
decryptInitTime += n2 - n1;
decryptUpdate1Time += n3 - n2;
decryptUpdate2Time += n4 - n3;
decryptDoFinalTime += n5 - n4;
}
long javaDecryptEndTime = System.currentTimeMillis();
System.out.println("Time init (ns): " + decryptInitTime);
System.out.println("Time update 1 (ns): " + decryptUpdate1Time);
System.out.println("Time update 2 (ns): " + decryptUpdate2Time);
System.out.println("Time do final (ns): " + decryptDoFinalTime);
System.out.println("Total bytes processed: " + javaDecryptInputBytes);
System.out.println("Java calculated at " + (javaDecryptInputBytes / 1024 / 1024 / ((javaDecryptEndTime - javaDecryptStartTime) / 1000)) + " MB/s");
}
EDIT: I leave it as a fun exercise to improve this simple minded benchmark.
I've tested some more using the ServerVM, removed nanoTime calls and introduced warmup, but as I expected none of this had any improvement on the benchmark results. It is flat-lined at 3 megabytes per second.
