Very slow performance of AES/GCM in JDK 8 SunJCE provider

[Anthony Scarpino]

Hi Tim,

CLMUL acceleration is being looked into.

Tony

On 03/27/2014 02:28 PM, Tim Whittington wrote:
> Hi all
>
> I’ve noticed that the performance of the AES/GCM implementation in the JDK 8 SunJCE provider is very slow.
>
> On a simple micro-benchmark (standard caveats etc. etc.) encrypting 10 MB blocks of random data (not decrypt) I get the following rough throughputs:
>
> AES/ECB +UseAESIntrinsics - 600 MB/s (btw this is awesome fast for Java, up from about 300 MB/s in Java 7)
> AES/ECB -UseAESIntrinsics - 120 MB/s (again a good bump from about 90 MB/s in Java 7)
> AES/GCM - 4 MB/s
>
> 4 MB/s is pretty catastrophic (especially compared to the stellar baseline AES performance).
>
> A quick peek in a profiler reveals pretty much all the time is in GHash.blockMult()/getBit()/shift().
> The performance of the AES/GCM mode is comparable to other pure Java implementations without table based multiplier optimisations (which typically provide speeds in the 40-60 MB/s on the same micro-benchmark).
>
> I wonder if the JDK implementation could adopt one of those approaches or (better) implement an intrinsic to speed this up (perhaps using the CLMUL interaction set when available).
>
> cheers
> tim
>
> —
>
> java version "1.8.0"
> Java(TM) SE Runtime Environment (build 1.8.0-b132)
> Java HotSpot(TM) 64-Bit Server VM (build 25.0-b70, mixed mode)
>
> Darwin <redacted> 13.1.0 Darwin Kernel Version 13.1.0: Thu Jan 16 19:40:37 PST 2014; root:xnu-2422.90.20~2/RELEASE_X86_64 x86_64
>