SQRC

Overview

SQRC (Secure QR Code) is a proprietary variant of the QR Code developed by DENSO WAVE INCORPORATED that adds a data-reading restriction. A single SQRC symbol carries two partitions: a public part readable by any ordinary QR Code scanner, and a private part that can be read only by a dedicated reader holding the correct cryptographic key [1]1 [2]2. Crucially, "Appearance of SQRC is no different from the regular QR Code" — the restriction is invisible, so the code does not visually advertise that it contains protected data [1]1. "SQRC" is a registered trademark of DENSO WAVE in Japan and many other countries [1]1.

History

SQRC is a derivative of the base QR Code symbology that DENSO WAVE (then a division of DENSO Corporation) announced in 1994 [3]3. The base QR Code was approved as an AIM standard in 1997, a JIS standard (JIS X 0510) in 1999, and an ISO/IEC international standard in 2000 — published as ISO/IEC 18004 [3]3 [4]4. SQRC was developed afterward "to meet users' demands for an enhanced level of privacy"; DENSO WAVE's history timeline does not give a specific introduction year for SQRC [3]3. By the time DENSO WAVE released its "Q" reader app and "Q platform" cloud service in October 2014, that reader could already decode SQRC alongside standard QR Code and the newly announced Frame QR, indicating SQRC predates 2014 [5]5.

Technical specification

SQRC builds directly on the standard QR Code data structure. According to community documentation of the encoding, the private content is placed in the symbol's data region after the standard terminator, in the space a normal QR Code would fill with padding bytes; this private segment is encrypted and requires a key to decrypt [6]6. Because the public part is encoded conventionally, an ordinary scanner reads it normally and simply does not surface the private part — which is why an SQRC "looks exactly the same as the regular QR Code" [2]2 [1]1.

Key technical properties stated by DENSO WAVE:

• Dual partition. "Data for SQRC consists of public part and private part," so one symbol stores information at two access levels simultaneously [1]1 [2]2.
• Reader-key requirement. The private data is protected by encryption and can be decoded only by "a dedicated reader having the cryptographic key"; "SQRC can be read only by specific types of scanners" [2]2 [1]1.
• No extra crypto step for the operator. "No additional encryption or decryption function is required" on the user side — the key handling is built into the SQRC reader workflow [2]2.
• Retains base QR features. SQRC "retains all standard functionalities including error correction" of the underlying QR Code [1]1.

DENSO WAVE is explicit about the limits of the mechanism: "This functionality does not guarantee that the coded data is secure" / "does not mean guaranteed securing of coded data" [1]1. SQRC restricts who can read the private partition rather than providing a cryptographic guarantee of confidentiality on its own. The vendor pages do not publish the encryption algorithm, key length, supported QR versions/models, or private-data capacity [2]2.

Use cases

DENSO WAVE and its subsidiaries describe SQRC as a way to combine externally-visible and internal/confidential data in one code, with applications including [2]2 [7]7:

• Event and venue access control — amusement parks, theme park rides, exhibitions, and entertainment facilities, where the hidden partition helps prevent forged or copied tickets [2]2 [7]7.
• Mobile ticketing — tickets distributed as QR codes whose validation data is restricted to authorized readers [2]2.
• Healthcare — protecting and managing patient personal information by keeping confidential fields in the private partition [2]2 [7]7.
• Delivery slips / logistics — separating internal company data from the externally-readable area on a single label [2]2.
• Internal / company-confidential data and access management, restricting which devices and users can read the protected fields [7]7 [1]1.

Implementations

SQRC tooling is essentially confined to DENSO WAVE's own commercial ecosystem: SQRC-capable generators and dedicated key-holding readers (including the "Q" reader app and "Q platform" service) are supplied by DENSO WAVE and its regional units [5]5 [7]7. Because the private-partition format and its key handling are proprietary and unpublished, there is no known open-source SQRC encoder or decoder. General-purpose open-source QR libraries (e.g. nayuki/QR-Code-generator, libqrencode, ZXing) implement only the ISO/IEC 18004 base symbology and do not produce or read the SQRC private partition; a same-named GitHub project, koutoftimer/sqrc, is an unrelated clipboard-to-QR display utility, not an implementation of DENSO WAVE's SQRC [6]6. Anyone wanting "secure" QR data with open tools must encrypt their payload before encoding it into a standard QR Code, which is a different construction from SQRC's invisible dual partition.

Comparison

SQRC vs. standard QR Code. A standard QR Code (ISO/IEC 18004) exposes all of its data to any scanner; an SQRC adds a private partition that ordinary scanners ignore and that only a key-holding reader can decode [1]1 [2]2. Visually the two are indistinguishable, which is itself a security property: an attacker cannot tell from a photograph that a code carries protected data, and the design helps deter forgery and tampering [2]2 [7]7.

SQRC vs. "encrypt-then-encode" QR. With a plain QR Code you can encrypt a payload yourself and encode the ciphertext — but the whole symbol then becomes unreadable to ordinary scanners (it shows gibberish). SQRC instead lets the public part stay openly scannable while only the private part is restricted, all in one code that still looks like a normal QR Code [2]2 [1]1.

Fun facts

• The hidden partition is designed to be undetectable to the naked eye: DENSO WAVE markets the fact that an SQRC "looks exactly the same as the regular QR Code" as an anti-forgery feature, since counterfeiters cannot see that protected data is present [2]2 [1]1.

Status

SQRC is a proprietary, actively marketed product of DENSO WAVE INCORPORATED, sold through DENSO WAVE and its regional subsidiaries; "SQRC" is a registered trademark of DENSO WAVE [1]1 [2]2 [7]7. It is not an ISO/IEC standard in its own right — it layers on top of the standardized QR Code (ISO/IEC 18004) — and generating or reading the private partition requires DENSO WAVE's licensed tooling and keys [1]1 [2]2.

Sources

1 SQRC | QRcode.com — DENSO WAVE, 2026. 2 SQRC® | QR Code Solutions | System Solution — DENSO WAVE, 2026. 3 History of QR Code — DENSO WAVE, 2026. 4 QR Code Standardization — DENSO WAVE, 2026. 5 DENSO WAVE Announces new QR Code with canvas area in the center — DENSO WAVE, 2014. 6 QR code — Wikipedia, 2026. 7 Security QR Code (SQRC®) — DENSO ADC, 2026. 8 What is an SQRC? — DENSO WAVE, 2026.

Deployments

No country reports mention this standard by name.

Regions / aggregations not mapped to a single country

• Universal