Another way to use QR codes

Foreword

After reading today a post about QR codes, and comments to it, I wondered, how else can you apply such a convenient tool in everyday life?
In the beginning, I just wanted to write a short description of the technology for the readers of my blog, with a few examples. But then the idea was born, which, I hope, will be close to the readers of Habr.

The essence

I, like many, love to keep my finances under control. I try to avoid unnecessary purchases and optimize costs. But for complete control, often there are not enough good and convenient software tools that allow you to visually manage the budget. Of course, there are quite a few such programs (I used my own tables in Excel for a very long time), but they all have one major drawback - the need to regularly and manually enter a huge amount of data. Usually, this ends up as the tables gradually become incomplete, and then, their maintenance ceases altogether.

However, this problem can be solved in a complex, using here such cash checks:

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How it will work

The first stage is printing on checks of QR codes. Since it is not expedient to enter the complete shopping list into the check, I suggest placing one single reference in the code. The link will contain an XML file containing a structured shopping list, with dates, prices, and number of purchases. The link will look like " domainname [long random string]". Naturally, the cash register at the same time, in addition to printing the code itself, must upload information to the server.

The second stage is the creation of a special mobile application that can scan a QR code and download a shopping list from the server. Also, you can use the "desktop" application, with a scanner or webcam, to receive data.

Thus, instead of self-entering information, we will need only a few keystrokes on the keys of the phone or computer.

In the case of the implementation of such a system, the user will be able to create various reports, because the check contains not only the list of goods, but also the price per item in a particular store. It will be possible to control the volume of consumption of products, since the check contains information on the quantity and volume. And all this will not need to be made manually.

Data confidentiality

The check itself does not have information that the buyer would like to hide (credit card numbers are not written on it completely), therefore, it is not even necessary to “filter out” the information before uploading to the server. Even if the link string is found by searching, the attacker will not know who exactly was the buyer. It is also impossible to compile any statistics on these files, since obtaining a large number of checks satisfying certain conditions will be almost impossible.

In addition, you can use the "lifetime" on the server for each check. Usually, a day is more than enough to add data to the local storage, especially if you are using a mobile phone.

Also, a good solution would be to use encryption to avoid attempts to intercept data over the network.

findings

I think the introduction of such a system would be a good step for manufacturers of software for cash registers. It will be an additional advantage over competitors, and will provide an excellent basis for upgrading a whole class of applications.

And of course, it will be another step towards meeting consumers.

upd: For this post in the sandbox I received an invite from PatapSmile , for which many thanks to him.