I have a PowerEdge 1950 with 2 x E5405 2.00Ghz CPUs and 4GB of RAM sitting around. It's currently not doing anything at all so it's a perfect fit for this task.

I have traditionally used 7-zip's command line tool on Windows to encrypt files that are no more than 5 GB. On my PC this doesn't take much time so it hasn't been a problem. Now, however, I need to start encrypting backup files that are 500GB+ in size and this will take a significant amount of time and resources if done locally.

I do not have a time limit for the encryption process so I could simply start 7-zip and let it run for a day on my PowerEdge but I'd really rather find a more efficient OS+tool to do the job.

On Windows I've tried AxCrypt and Kryptel but they were not any faster.


To clarify this question a little... the heart of what I'm trying to get at is suggestions for proven tools and OS (if that matters) for encrypting files that will be sent offsite for archival storage. In my case I will be sending them to Amazon Glacier so full-disk encryption is not appropriate.

closed as not constructive by TheCleaner, Ward, HopelessN00b, Rob Moir, Dave M Feb 15 '13 at 21:38

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  • 1
    At the risk of providing a useful suggestion... why don't you either use a backup utility with built-in encryption, or store them on an encrypted disk or partition? Any decent backup suite allows use of encryption, and there are native tools in both Linux and Windows that afford encryption, not to mention the sea of 3rd party crypto tools, Like Truecrypt. – HopelessN00b Feb 15 '13 at 19:54
  • @HopelessN00b Veeam Backup & Replication is creating the backup files and it does not have encryption (they want the user to handle it). The files will be sent to Amazon Glacier for archival storage. Therefore, at-rest encryption (correct term?) is what I need to achieve. – Chris76786777 Feb 15 '13 at 20:03
  • Ah, that's a good reason. In which case, I'd suggest that your best option is the one suggested in the answer by @MirceaVutcovici . Grab a bunch of file level encryption tools, benchmark them on your system, and pick the one that works best for your needs. – HopelessN00b Feb 15 '13 at 20:17

The performance depends on:

  • Encryption algorithm. The NULL one is the fastest, but has a trade off: it is completely insecure.
  • The implementation of the algorithm (is it multi-thread, is it using the CPU extensions, how much memory is using - this is affecting the CPU cache hit ratio)
  • The speed of the CPU and the extension it is supporting (LM, MMX, SSE)...
  • The speed of the I/O subsystem (disk, network, FSB, PCI Express)

The tool is not that important as it is the libraries that are implementing the algorithm. The OS is not that important as most of the job is run in user space, only 64 bit/32 bit support can affect, depends on the algorithm implementation.

So the real answer to this is: benchmark for yourself.

Your CPU does not seems to support AES acceleration (like this one). You could search for a software that is offloading the calculations in the GPU. See:

  • You make some strong arguments but the piece you're neglecting, which is most important for me here, is the "for yourself" part. I can only do that if I have the tools to do it with and that is what I am looking for. Without suggestions for said tools I can't move on. 7-Zip does AES-256 but does it use the available hardware to its maximum capability? I don't know and that's what my question is for. – Chris76786777 Feb 15 '13 at 20:12
  • All the programs are using the entire hardware capacity. If it is efficient, this is another question. The efficiency should be tested with benchmarks on your hardware. There are too many variables and you have to test by yourself. – Mircea Vutcovici Feb 15 '13 at 20:16
  • You need to do the benchmarks on your environment. I've seen cases when the same program was running fine on a slow VM and very slow on the production server that was a physical machine with much more resources to spare. All caused by an index that was missing in prod. – Mircea Vutcovici Feb 15 '13 at 20:19
  • I feel like I'm failing to communicate here... The tool IS important because that is what performs the encryption. Without suggestions for tools, beyond what I have already used, I can not benchmark further. I think you are failing to see beyond the words in my title to find the intent of my question. See my newly edited title. Perhaps it will help clarify. – Chris76786777 Feb 15 '13 at 20:46
  • Here is a lost of software that supports AES: en.wikipedia.org/wiki/AES_instruction_set#Applications – Mircea Vutcovici Feb 15 '13 at 21:12

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