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What is a gift certificate maker or gift card generator?
What can I do with the AI Gift Card Generator?
How much does it cost to create a gift card with the gift card designer?
I'm just looking for any type of way for a playstation gift card and/or a present for my gf, but literally have not a single cent to my name and can't get any for another 5-ish months, so I've turned to the internet, which was my first mistake of many. My naive ass thought some gift card generators were real untill it started asking to download a bunch of apps, which is a hard no.
The likelihood of two randomly generated code colliding is basically the same as a user guessing a valid code - and you cannot prevent users from guessing. So you must have a key space so much larger than the number of actually used codes that random collisions are extremely unlikely as well (though, thanks to the birthday paradox, probably not unlikely enough to ignore them completely, at least if you want your codes to be reasonably short), and checking against existing codes and re-generating in case of a collision is a perfectly viable strategy.
Use an N-bit serial number R, combined with an M-bit hash H of the concatenated pair (R, S) where S is some secret "salt" S which you do NOT publish. Then encode the pair (R,H) alphanumerically in any reversible way you like. If you like algorithms like MD5* or SHA, but the bit count is too high, then just take the M least significant bits of a standard hash algorithm.
You can verify easily: decode the alphanumeric encoding so you can see R and H. Then compute H' = hash(R+S) and verify that H = H'.
edit: R can be an incrementing serial number or random or whatever, just make sure you use each value not more than once.
*before someone says "MD5 is broken", let me remind you that the known weaknesses for MD5 are collision attacks, and not preimage attacks. Also, by using an unpublished, secret salt value, you deny an attacker the ability to test your security mechanism, unless he/she can guess the salt value. If you feel paranoid, pick two salt values Sprefix and Ssuffix, and calculate the hash of the concatenated triple (Sprefix,R,Ssuffix).
So lately I've been using the Costco gift cards pretty regularly. The only issue is that it's 4 $50 gift cards, and each one has a 19 digit code plus a 4 digit pin, which staff have to enter in manually, one by one.
If you want to buy the most expensive package available, you need to have them ring up at least 3 separate gift cards which can be time consuming and also just annoying for staff to have to deal with.
But I've found the solution. You can actually use the gift card codes to generate working barcodes for staff to scan instantly. :)
Here are the instructions:
Visit https://orcascan.com/tools/free-barcode-generator/code-128 (there are other barcode generator sites but this one is simple and clean and to the point)
The barcode type should be 128, which should be automatically set when using that link
In the "Barcode content" enter in the 19 digit gift card number
In the "Barcode caption" I just paste in the same 19 digit number and also write in "Pin: 1234" (with the actual pin code there) just in case for some reason the barcode won't scan, the staff still have the entire number and pin right there.
Right click and save the generated barcode image or click the Download button
Put the image on your phone. Preferably make a separate folder for gift card codes just to make it simple.
Now when you go to D&B just walk up and open that barcode image and the staff can instantly scan your gift card. Saves SO much time if you're cashing in multiple gift cards in a visit. Enjoy!