Re: Needle in a haystack--or is this just stupid?

From: Tom St Denis (tomstdenis_at_gmail.com)
Date: 07/03/05 

Date: 2 Jul 2005 19:58:09 -0700

Cry...@S.M.S wrote:

> With more modern computers, that is simply not the case.
> While RAM and Time are limited, there is plenty of both
> to run as many overlapping algorithms as you want.
>
> CryptoSMS uses 6 hashes and 3 ciphers, and it still only
> takes it a second to encrypt a 140 byte SMS message. Less
> time than it takes to send/receive such a message, so the
> encrypt/decrypt appears transparent. These are speeds on
> a 300 mHz Pocket PC, which is not a lot of processor.

140 bytes/second is not a throughput to be proud of on a 300Mhz ARM
processor. IIRC my Blowfish C code from an early LTC hit ~520Kbit/sec
at [effectively] 8Mhz on an ARM7TDMI. Scaling that to 300Mhz with
zero-wait 32-bit data should hit roughly 2.38MiB/sec A mere 17828
times faster than what you are claiming :-)

I know you're accouting for the entire sending process but my point is
a 140 byte message should take <10K cycles to process.

Your comments lead me to think you've never had to engineer software on
tightly constrained platforms...

Tom

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