SQR codes

trademark for a type of matrix barcode

Secure Quick Response codes or SQR codes are secure two dimensional barcodes with high data density, based on QR codes. [1]

Example of an SQR code (This page)
Another example of an SQR code

Secure Quick Response codes are a secure method for encrypting data into a barcode. It makes it extremely difficult to decode into the original plain text in the absence of the encryption cipher or key. A typical implementation of SQR codes would be to create a one-time use SQR code on a mobile phone's screen to effectively create a highly secure one-time pad type of encryption of, for example, an online account number.

A typical implementation is to encrypt and use a precursor physical machine readable token such as the card identity number (CID) written in read-only memory (ROM) of a Secure Digital microSD card contained in a mobile telephone. The international mobile identity number may be used where no microSD card is present, for example, on an Apple iPhone.

SQR codes may be securely read in a retail environment at the point of sale using 2D barcode scanners or even a low cost web camera. Secure Quick Response codes were first developed by Yodo, a company operating in Japan, and are patent pending.


  1. Goel, Nishant; Sharma, Ajay; Goswami, Sudhir (2017-05). "A way to secure a QR code: SQR". 2017 International Conference on Computing, Communication and Automation (ICCCA): 494–497. doi:10.1109/CCAA.2017.8229850. Check date values in: |date= (help)