Re: Crypto Hardware for Loop-aes?

[Jan Luehr <jluehr@xxxxxxx>]

Hello,

Am Dienstag, 8. November 2005 17:56 schrieb Boyd Waters:
> On Nov 8, 2005, at 4:28 AM, Venkat Manakkal wrote:
> > http://hifn7751.sourceforge.net/
>
> I tried the Soekris card on FreeBSD; both OpenBSD and FreeBSD use a
> kernel-level cryptographic framework that can use these PCI hardware
> accelerators (hifn chips).
>
> They are not appropriate for on-disk encryption.
>
> I don't have the details correct, but it is a performance issue: data
> must transferred from main memory via the CPU to the PCI card for
> processing, and then the data is transferred back, and then it is
> written to disk.

USB 2.0 has 400Mbit (50 Mbyte) per sec. HD has ~ 20MB. If you just encrypt i/o 
-data, this shouldn't be an issue.

> The accelerator cards are more appropriate for network packet
> encryption: the network stack could tell a network interface to
> perform direct memory transfer to the crypto card on the PCI bus
> before ever hitting the CPU or the main memory. In that application,
> one could achieve "wire-speed" encryption of the network packets,
> without CPU overhead.
>
> My experience is that for disk I/O, crypto operations of the CPU are
> still faster than the PCI-based crytpo accelerators.

Ok..

> This almost certainly does NOT apply to the VIA "padlock" crypto
> acceleration, which adds instructions to the x86 ABI and performs
> crypto operations on the CPU.

> {Open, Free}BSD is a fun system to use if one is concerned about
> security and robustness. But I have not found a disk-encryption
> solution that rivals loop-aes on Linux for performance and stability.

Ok.

Thanks, 
Keep smiling
yanosz 

-
Linux-crypto:  cryptography in and on the Linux system
Archive:       http://mail.nl.linux.org/linux-crypto/