B
Barry
HI,
I'm building a system where I wish to give my users a unique code each
time they perform a transaction. On returning to my system, they can
then enter this code to retreive the data associated with it.
I number my transactions in assending order, 0, 1, 2 and so on, so I
need a function that will transform this value to a unique nine digit
number. I also need a function that will transform this value back
again to the transaction number.
Something like this -
long codeTransactionNumber(long transactionNumber)
{
return transactionNumber + 100000000;
}
long uncodeTransactionNumber(long transactionNumber)
{
return transactionNumber - 100000000;
}
Thie problem with this though is that the user with the code
100-000-003 can easily guess that 100-000-004 is also a code for
another transaction. What would be a better way to generate this
number?
Also, I should point out that the number of clients that this system
has is very low - 5 per day max. Also, they enter the code using a
touch screen interface so entering many codes is difficult.
Thanks for your advice,
Barry
I'm building a system where I wish to give my users a unique code each
time they perform a transaction. On returning to my system, they can
then enter this code to retreive the data associated with it.
I number my transactions in assending order, 0, 1, 2 and so on, so I
need a function that will transform this value to a unique nine digit
number. I also need a function that will transform this value back
again to the transaction number.
Something like this -
long codeTransactionNumber(long transactionNumber)
{
return transactionNumber + 100000000;
}
long uncodeTransactionNumber(long transactionNumber)
{
return transactionNumber - 100000000;
}
Thie problem with this though is that the user with the code
100-000-003 can easily guess that 100-000-004 is also a code for
another transaction. What would be a better way to generate this
number?
Also, I should point out that the number of clients that this system
has is very low - 5 per day max. Also, they enter the code using a
touch screen interface so entering many codes is difficult.
Thanks for your advice,
Barry