"Mok-Kong Shen" schrieb im Newsbeitrag ...


John Hadstate wrote:

(Matthew) wrote in message
Access to the information is only possible using secret keys
specific to that card, known only to devices permitted to process the
cards. These cards are very difficult to break into, making the cards
very secure; in the unlikely event that a card has its key broken
then the system - and all other cards - will remain secure.


All of the above adds up to a classic case of "security by obscurity."
This might mean that the inventors have already identified or suspect
weaknesses in their system that they hope will remain undiscovered if
no one is permitted to analyze their system too closely.

On the other hand, if the cost/risk of analysis is
sufficiently high, there would be 'practical' security,
I suppose. (Actually, banknotes are similar in this
respect, I believe. There are saying, though, that
the techniques/knowhow of the fraudsters are now quite
comparable to those of the governments in making
banknotes.)
Actually, today banknotes aren't naively stuffed fithe anti-forgery-features
but the idea is to make it unprofitable to fake a banknote in a small-scale
production. So, a forger is forced to go large-scale which in turn is easily
detectable (duplicate serial numbers or unexplainable inflation for instance)
and which also justifies a large-scale counteraction to find and disable him.

Lots of Greetings!
Volker

Volker Hetzer wrote:


Actually, today banknotes aren't naively stuffed fithe anti-forgery-features
but the idea is to make it unprofitable to fake a banknote in a small-scale
production. So, a forger is forced to go large-scale which in turn is easily
detectable (duplicate serial numbers or unexplainable inflation for instance)
and which also justifies a large-scale counteraction to find and disable him.

I am not sure duplicated serial numbers or unexplainable
inflation, especially the latter, are practical
characteristics that are 'effectively' checkable.
(Define 'unexplainable inflation'!) It's 'olds' now that
e.g. 50 Euro banknotes had been forged quite well. They
were presumably produced in regions not within EU
influences. Someone told me that certain sophisticated
techniques previously employed in DM are not used in Euro
because Euro is made by diverse member countries and not
all of them had such techniques at their disposal and so
they agreed on sort of a gcd.

M. K. Shen