0012100

[vbud]

hmmm...could anybody please explain to me what is the matrix 0012100 and where is it commonly used??? I believe some security check features use this, can someone confirm that?

thanx

[jim mcnamara]

I'm used to seeing polynomials in C notation. This looks like one of the ones used for CRC checks - like the FDDI one. But I'm not sure. It could be anything - because it's totally out of context.

Where did you find it?

[vbud]

It seems to me that it is used in Prepaid phone cards for counter checking validity of a phone card number. But i'm not sure of the usage. Looks like i'll have to perform some more research about this...anyway thanx.

[jim mcnamara]

It is a polynomial for a CRC check - don't know which one.

[Spooner]

Originally posted by jim mcnamara
This looks like one of the ones used for CRC checks - like the FDDI one.

I believe the FDDI poly is 04c11db7 hex, which is 32 bits namely:
00000100 11000001 00011101 10110111,

or 79764919 decimal.

Nor is it X25 standard or reversed, nor CRC16 standard or reversed according to my reference.

Google didn't help, either.

[Judd]

Looks like a line from Pascal's Triangle to me...

[vbud]

What is a Pascal triangle???

[Judd]

Its used to find coefficients in binomial expansion, along with many other things:

    1
   1 1
  1 2 1
 1 3 3 1
1 4 6 4 1

Each line number being the sum of the two directly above it.

Look at

http://mathworld.wolfram.com/PascalsTriangle.html

[Spooner]

Pascal's triangle is a triangle of numbers where any number in a line is the sum of the numbers above it, to the left and right.

It starts with 1 on line1, then 11 on line2 to get going, then line3 is 121, the 2 being the sum of the 2 1s above it. Then line4 is 1331, the 3s being the sums of the 1s and 2s above.

In code below the numbers might line up:

          1
         11
        121
       1331

etc

The rightmost line of 1s is supposed to slope too!