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List Info Thread: Philips/NXP/Mifare CRYPTO1 mostly reverse-engineered
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Philips/NXP/Mifare CRYPTO1 mostly reverse-engineered |
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List Info Thread: Philips/NXP/Mifare CRYPTO1 mostly reverse-engineered
[1-4]
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about | contact Other archives ( Real Estate discussion Medical topics ) |
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metzdowd.com
![http:// www.zooomr.com/photos/ralf/sets/26758/](http://cryptanalysis.eu/blog/2007/12/29/mifare-crypto1
<img
src='http://www.archivesat.com/images/blushing.gif'>http://c
ryptanalysis.eu/blog/2007/12/29/mifare-crypto1:</a>
"MiFare’s CRYPTO1 stream cipher has captured my
attention for a while.
However, hardware reverse-engineering is not a field I
actively engage
in. So I was very happy when Karsten Nohl (University of
Virginia),
Starbug and Henryk Plötz gave a talk at the 24C3 [the 24th
Congress of
the Chaos Computer Club taking place in Berlin at this very
moment]
yesterday evening showing that they have reverse-engineered
most parts
of this cipher. CRYPTO1 uses a 48-bit LFSR-based filter
generator to
generate key stream.
The filter function - if I understood correctly - uses 20
taps (this
was not mentioned in the talk, I asked Karsten privately
about this)
however the degree of the boolean function implementing the
filter,
thus it remains to be seen whether algebraic attacks can be
applied.
Even if no algebraic attacks are applied, a BSW sampling
TMTO will
break CRYPTO1 completely. This was pretty obvious before
they gave
their talk, but now vendors actually have to worry about
this being
out in the wild once the feedback and the filter function
have been
revealed.
My colleague Erik took photos of the slides which I put up
on Zooomr
[0]. A video recording of the talk should be available
shortly and
will be linked here."
[0] <a
href=){kind=link}