how does a recharge voucher works
hi friends today let us see the actual working of the recharge voucher works...............
Hello friends,
There is no complete verification o the
method followed by the topmost companies which offers coupons such as recharge
cards for commercial purpose or recharge.. But here is a method which is
accepted globally by maximum number of people.
1. Permutation
2.hamming and security
3. VMC
these
are the key-steps for the management of the recharge vouchers.
In this process the recharge coupons were
permutated for the year of manufacture, that means vouchers were made for once a
year as they will be expired after one year. Then the nearly 10% of the coupons
were made out the permutated coupons.
Now I will give a detailed mathematical
explanation on the above steps and elaborate the steps completely
Consider a large country like India and a
service provider like say some company "X"
1.permutation
The recharge voucher consists of 16 digits
and it can be permutated such that it consists of
0-9 numbers with repetition..
Soo the total number of permutations is
9×10^15=90000000000000000=900, 000 billions or 9 lakh crores
Its clear now
comes to demand the total number of
population is 1.4 billions or
140 crores(approximately)
In an average every Indian needs 3 recharge
voucher a week
So total vouchers used per year =
3× 52 Weeks×1.4 billions=218.4 billions
<<note:we calculate for year because
every coupon expires after one year>>
So the chances of occupancy is
(900000/218.4) =4,120
So the conclusion is for every 4, 120
coupons one will be selected
The way of selection is described below..
2.hamming
and security
In the
second phase the selected number of coupons were printed with a unique code
Which
always exists with respect to the serial number of the code followed by a
strong algorithm. In this case we use a concept called hamming distance the
below example illustrates the concept of hamming..
Hamming
means the changes made in the uniform manner between the length of the strings
or another words change in string distance.
After the
hamming process then the 12 digits of the voucher is supported by a 4 digit pass-code (since the total number of digits were 16)
The
hamming distance is also applicable for them too..
For
example consider two alternate recharge vouchers
The card
we have chosen is
Now
consider the next voucher of alternate serial number
In the above example
In the above example
The
difference between the two cards is highlighted
"2"
indicated the security code of the voucher..
3. VMS
The
trickiest technique is vms (voucher management system)
A limited
number of coupons were entered to the server or any working main frame system
of the company for a limited time say one month in advance.. As the codes works
with the serials which have entered in th vmc only works since the rest of them awaiting for their activation..
I think
you dont need an example for this as all of you have experienced that sometimes
your recharge voucher doesn't work and when you call your customer-care or
service provider they asks your serial number and it works within a minute all
this because of this vmc.
