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Re: [openpgp] AEAD Chunk Size

2019-03-28 23:40:28
On 3/29/19 at 8:33 PM, pgut001(_at_)cs(_dot_)auckland(_dot_)ac(_dot_)nz (Peter 
Gutmann) wrote:

Bill Frantz <frantz(_at_)pwpconsult(_dot_)com> writes:

The Arduino Uno, which the web site says is the most popular Arduino in the
line
<https://store.arduino.cc/usa/arduino-uno-rev3>, has:

Flash Memory 32 KB (ATmega328P) of which 0.5 KB used by bootloader
SRAM 2 KB (ATmega328P)
EEPROM 1 KB (ATmega328P)

So it might be able to use a chunk up to 1KB without having to do the kind of
pipelining that leads to security bugs and messy code.

And where does the PGP code and data memory itself fit in all this?

Peter.

Well, we had a version of PGP running on an original IBM PC. With careful implementation, you might get the code into 32K program memory using the 2K R/W memory for buffers and working memory. You also might slip implementing all of the SHOULDs and perhaps some of the inappropriate MUSTs. You would probably have to also always make the tradeoff for space and not performance.

Remember, the original question was asked by an enbedded system developer. How small do they go? If they're looking at Raspberry Pi size machines, then they really have it comparatively easy.

Cheers - Bill

------------------------------------------------------------------------
Bill Frantz |"Insofar as the propositions of mathematics refer to 408-356-8506 | reality, they are not certain; and insofar they are www.pwpconsult.com | certain, they do not refer to reality.” -- Einstein

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