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ameir / lowes-coupon-generator

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New formula #2

Open andyl913 opened 5 years ago

andyl913 commented 5 years ago

Hi, Lowe's recently changed their $20 off $100 algorithm to generate the digits before the 4 digit signature towards the end. Do you have an update for this tool to calculate the $20 off $100 codes using the new algorithm along with the new $20 off $100 signatures?

ameir commented 5 years ago

Do you have any more info on this new algorithm?

andyl913 commented 5 years ago

Unfortunately I do not. I was hoping that maybe I could find it here. I have talked with some eBay sellers though and learned that there are many different "pools" of codes that can be created based on the middle numbers.

ameir commented 5 years ago

Rather than a new algorithm, it seems that they're storing pre-computed codes and cross-checking them, versus simply accepting unused codes that match their algorithm.

I was able to get working codes with the following:

- signature: "2080"
  prefix: "47132"
  description: $20 off $100
  expires: 12/27/2018
  max: 10
andyl913 commented 5 years ago

Oh wow that's interesting. Out of the hundreds of codes I purchased, I did find some that were very close together (the middle numbers being around 120-170 apart. I added or subtracted the difference to come up with a new code to see if I can find anymore in the sequence, and then I would recalculate the check digit. I could only go about 1 code higher or lower then it wouldn't work anymore.

I'll give an example.

47133870332080 - notice 7033

47133871452080 - notice 7145 (112 apart)

47133872572080 - I added 112 and got 7257

I calculated the checksum on the last code and it worked. It just so happened all 3 of these checksums were 0, but that is not always the case as I have discovered. They could very well be using some type of cross-checking program (which I figured they would have), but they are still using some type of algorithm to mass calculate that list.

From someone who knows how to get the new $20 off codes:

"Not sure how long you've purchased Lowes coupons but there was a recent change to their system that makes it extremely difficult to locate and identify updating codes.

I've been working on some updates since their change, which has been about 10 days. Most other sellers have what I call "colliding coupons". Meaning they are all using codes from the same pool and sell coupons that could already be used/sold by someone else. As if this morning, I have a workaround and in almost all instances never have a coupon sold as "already used". It's not simple and requires constant updates and tweaks."

On Thu, Nov 29, 2018 at 11:27 PM Ameir Abdeldayem notifications@github.com wrote:

Rather than a new algorithm, it seems that they're storing pre-computed codes and cross-checking them, versus simply accepting unused codes that match their algorithm.

I was able to get working codes with the following:

  • signature: "2080" prefix: "47132" description: $20 off $100 expires: 12/27/2018 max: 10

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/ameir/lowes-coupon-generator/issues/2#issuecomment-443087149, or mute the thread https://github.com/notifications/unsubscribe-auth/ArXJyi4D0E9pqGB3i71hbVP_gKqVmmvjks5u0LObgaJpZM4Y6XOr .

andyl913 commented 5 years ago

Rather than a new algorithm, it seems that they're storing pre-computed codes and cross-checking them, versus simply accepting unused codes that match their algorithm.

I was able to get working codes with the following:

- signature: "2080"
  prefix: "47132"
  description: $20 off $100
  expires: 12/27/2018
  max: 10

I built a validator tool using this information and came up with a pool of codes that worked, but as of today that does not work anymore, and I have tried updating the prefix with other working codes and verified that the signature still works. Not sure what is going on.

Also, I found out today the new 10% off coupon uses 47142xxxxx at the beginning.

steve20182 commented 5 years ago

I built a validator tool using this information and came up with a pool of codes that worked, but as of today that does not work anymore, and I have tried updating the prefix with other working codes and verified that the signature still works. Not sure what is going on.

Also, I found out today the new 10% off coupon uses 47142xxxxx at the beginning.

Rather than a new algorithm, it seems that they're storing pre-computed codes and cross-checking them, versus simply accepting unused codes that match their algorithm. I was able to get working codes with the following:

- signature: "2080"
  prefix: "47132"
  description: $20 off $100
  expires: 12/27/2018
  max: 10

I built a validator tool using this information and came up with a pool of codes that worked, but as of today that does not work anymore, and I have tried updating the prefix with other working codes and verified that the signature still works. Not sure what is going on.

Also, I found out today the new 10% off coupon uses 47142xxxxx at the beginning.

Hi Andyl913 , Could you please share your validator tool that you build I really need something like this , manually checking codes is taking so long . I have 2 more prefixes that are working .