Ford M Algorithm

[amilo]

I am interested in the mathematics of the algorithms behind the various radio code calculators and am currently looking at the readily available Ford M Calculator.

Does anyone on here know and is willing to explain fully the details behind the Ford M algorithm ( and also the Blaupunkt Standard code algorithm) as I understand both use look-up tables.

I`ve read through the previous postings on this subject and unfortunately didn`t fully understand them.(mainly the derivation of the lookup tables)

If this information is not to be discussed on the open forum then please send me a PM

I am willing to offer a few beer tokens to anyone who can provide explanations that allows me to understand more fully the methods used.

Cheers

[elektro128]

http://www.digital-kaos.co.uk/forums/f176/ford-v-series-calculator-153206/#post721007

[amilo]

http://www.digital-kaos.co.uk/forums/f176/ford-v-series-calculator-153206/#post721007
Thanks ..I`ve seen that explanation but do not understand where the digits came from in the 10 x 10 look-up table.

(I can understand the rest)

Does anyone know?

[alexics]

Ford decided what to put in that table. It is static and never changes.

[amilo]

Ford decided what to put in that table. It is static and never changes.



I would assume that there must be some logic in the numbers selected.

If not , then it appears to be a random 10x10 so how on earth did anyone manage to crack it?

Was it inside information from Ford or Visteon?

[alexics]

I would assume that there must be some logic in the numbers selected.

If not , then it appears to be a random 10x10 so how on earth did anyone manage to crack it?

Was it inside information from Ford or Visteon?

The decode fairy took pity on someone because they seemed so nice and needed a little boost to cheer them up.

[alexics]

So one night this person put a Visteon radio under their pillow. In the morning they were sad that it had gone. Until they realised that the kind decode fairy had given them the keys to the king's counting house. Then it was beers all round.

[Dunker]

Jees Alex, and I thought I was the only one still up at stupid oclock in the morning. It must be the V series....


I would assume that there must be some logic in the numbers selected.

If not , then it appears to be a random 10x10 so how on earth did anyone manage to crack it?

Was it inside information from Ford or Visteon?

In this case the key table is random, but not totally. By totally I only mean that if you take a look at the rows versus the columns you can see each number appears one once in each row/column.

A bit like:

3 5 4 1 2
5 2 1 3 4
1 4 2 5 3
4 3 5 2 1
2 1 3 4 5

I just did this in less than a minute. Try an array of 16x16 or even 32x32.

Some might consider non repeating digits a weakness :smokin:

I can remember years ago when I was figuring out the old Alpine Jaguar 9 series radios coding from the pads. It took me ages thinking about it before I realised that no digit was repeated in a code. This cut the possibilities down astronomically.

As for the key table/algo etc. I think alexics has answered that one.

[M1DJF]

nice one:celticparty:



So one night this person put a Visteon radio under their pillow. In the morning they were sad that it had gone. Until they realised that the kind decode fairy had given them the keys to the king's counting house. Then it was beers all round.