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Questions tagged [barcode]

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47 votes
7 answers
16k views

How resistant are barcodes and QR-codes against attempts to change stored data?

Assume we want to protect a document against manipulating and forging. So, we encode some sensitive information of the document and store it in a QR-code inserted in the document. Can we be sure that ...
2 votes
1 answer
538 views

Avoid QR/Barcode duplicates for fake product identification

I'm developing an app for a college project to detect fake products. The idea is to scan a QR or barcode and the app will automatically tell you if the product is either original or fake. How to avoid ...
49 votes
21 answers
21k views

Are there unphotographable, but scannable ID cards?

We have a client who hosts an event, with a tight budget, that uses lanyarded Photo-ID cards with barcodes on them. The barcodes are used to gain access to various areas at the event. We were ...
5 votes
1 answer
864 views

Safety of barcode checksums

A company is handing out gift vouchers with a unique code128 barcode. The barcode consist of 12 fixed characters containing meta information and sequence number plus a 4 digit checksum. For example: ...
4 votes
3 answers
362 views

Using a simple 5-character pass for event vs. QR/barcode

I plan on doing a "ticketing" system, where a user would buy a "tour ticket" online. The part that I'm puzzled about is: After they buy, what mechanism to use to verify the ticket? I've been looking ...
0 votes
3 answers
2k views

How to encode user authentication in a barcode

I was suggested to post here from this question in Super User SE. So here is the copy of it: I'm asked to add the possibility to scan a barcode (on a badge) to authenticate users when they log in to ...