Re: aes performance

[Scott Bennett <bennett@xxxxxxxxxx>]

     On Mon, 23 Feb 2009 16:59:21 +0100 slush <slush@xxxxxxxx> wrote without
proper attribution (tsk, tsk):
>Tor FAQ: I have more than one CPU. Does this help?
>Yes. You can set your NumCpus config option in torrc to the number of CPUs
>you have, and Tor will spawn this many cpuworkers to deal with public key
                                                                ^^^^^^
     AES is a symmetric-key cipher, not an asymmetric-key cipher, so there
are no "public key" operations involved in AES encryption/decryption.
     The answer shown in the FAQ is poorly stated.  Rather than "Yes.", it
should have said, "Not very much.  It only makes much difference on extremely
high throughput systems, where onionskins may be queued for decryption far
faster than a single processor might be able to keep up with.  It also keeps
onionskin decryption operations from interfering with other tor processing by
moving those operations off of the core is handling the rest of tor's work."

>operations in parallel.


                                  Scott Bennett, Comm. ASMELG, CFIAG
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