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IEC 11694-5-18 (ISO/IEC 11694-5:2018): Data Format for Information Interchange on Optical Memory Cards
A comprehensive technical overview of the linear recording method data format standard for optical memory cards
Scope and Application
IEC 11694-5-18, formally adopted as CAN CSA ISO IEC 11694-5-18, specifies the data format for information interchange on optical memory cards that use the linear recording method. This standard is part of the multi-part ISO/IEC 11694 series, which defines identification cards with optical memory capabilities. The Data Format for Information Interchange (Part 5) establishes the logical structure, coding rules, and interchange requirements to ensure interoperability between optical memory card systems from different manufacturers.
The standard applies to cards that comply with the physical, dimensional, and optical properties defined in earlier parts of the series (ISO/IEC 11694-1 through 11694-4). Specifically, it targets applications in secure identification, healthcare records, personal data storage, and access control, where reliable, high-density data interchange is required.
Key Application Domains: Healthcare card systems, government-issued identification, secure access credentials, and portable personal data storage.
Relationship to the ISO/IEC 11694 Series
| Part | Title | Standard Reference |
|---|---|---|
| 1 | Physical characteristics | ISO/IEC 11694-1 |
| 2 | Dimensions and location of the accessible optical area | ISO/IEC 11694-2 |
| 3 | Optical properties and characteristics | ISO/IEC 11694-3 |
| 4 | Logical data structures | ISO/IEC 11694-4 |
| 5 | Data format for information interchange | IEC 11694-5-18 |
| 6 | Use of biometrics on an optical memory card | ISO/IEC 11694-6 |
The standard is designed to be used in conjunction with Part 4 (logical data structures) and Part 1–3 to form a complete specification for optical memory card systems.
Technical Requirements
Data Structure and Format
IEC 11694-5-18 defines how data shall be organized within the optical memory card’s linear recording zones. The standard specifies:
- File structure: Hierarchical organization using directories and files, similar to common file systems.
- Record format: Fixed-length and variable-length record support, with mandatory file descriptors.
- Data encoding: Use of ISO/IEC 646 (ASCII) for textual data and binary coding for signed and unsigned integers, floating-point numbers, and date/time values.
- Error detection and correction (EDC/ECC): Requirements for Reed-Solomon codes capable of correcting burst errors typical of optical media.
- Data integrity markers: Checksums and cyclic redundancy checks (CRC) for each data block and file.
- Interchange header: A mandatory header at the beginning of each logical track containing card identification, format version, and data structure pointers.
Implementation Tip: The standard mandates that all implementations must support a minimum data block size of 512 bytes, with the ability to reassign blocks in case of media defects.
Logical Track Layout
The linear recording area is divided into logical tracks. Each track consists of a header zone, data zones, and an error correction zone. The standard specifies the exact sizing and placement of these zones relative to the card’s physical reference edges.
| Zone | Function | Typical Size |
|---|---|---|
| Header Zone | Track identification, formatting information, and pointers | 512 bytes |
| Directory Zone | List of files and their attributes (name, type, permissions) | Up to 16 KB |
| Data Zone(s) | User data organized in blocks and records | Up to several MB |
| ECC Zone | Reed-Solomon parity symbols | Typically 10%–15% of data |
Format Version and Compatibility
IEC 11694-5-18 introduces a versioning mechanism in the interchange header. Implementations must read and write the version field to ensure forward and backward compatibility with future editions of the standard. The current version (2018) uses version identifier 0x01.
Legacy Cards: Cards formatted according to the previous edition (2006) include a conversion table in the directory zone; readers compliant with IEC 11694-5-18 are required to detect and correctly interpret the earlier format version.
Implementation Highlights
Device and Software Requirements
To fully implement the standard, both the card reader/writer hardware and the controlling software must support:
- Linear recording method: Optical head positioning to read/write multiple parallel tracks.
- Data rate: Minimum read speed of 100 KB/s and write speed of 50 KB/s for interchange.
- Error handling: Retry and reallocation strategies for defective blocks.
- Security: Optional support for access control lists (ACLs) and digital signatures per file.
Interoperability Testing
Implementers are encouraged to perform conformance testing using reference data sets. IEC 11694-5-18 includes normative annexes with test vector examples for file structure verification and ECC correctness. Many national adoption bodies (e.g., CSA in Canada, ANSI in the US) provide testing services or recognize accredited laboratories.
Certification Programs: Several industry associations offer card and reader certification based on this standard, ensuring cross-vendor interoperability for sensitive applications like e-health and e-government.
Compliance and Certification Notes
Normative References
The standard references the following essential documents:
- ISO/IEC 11694-4: Logical data structures
- ISO/IEC 646: ISO 7-bit coded character set
- ISO/IEC 9787: Information technology — Digital data exchange — File structure and labeling
- ISO/IEC 10373-5: Identification cards — Test methods — Part 5: Optical memory cards
Testing Procedures
Compliance with IEC 11694-5-18 must be verified using the test methods defined in ISO/IEC 10373-5. Key test parameters include:
- Correct rendering of the interchange header and directory.
- Successful data encoding/decoding for all mandatory data types.
- ECC performance under standard error injection (frame error rate up to 10-3).
- Mechanical and environmental endurance of the optical recording layer after repeated data interchange cycles.
Canadian Adoption (CSA)
The Canadian Standards Association has adopted this international standard as CAN CSA ISO IEC 11694-5-18 without deviation. This adoption streamlines the approval process for products intended for the Canadian market, as compliance with the international version automatically satisfies the Canadian national requirement.
Important: Organizations seeking to certify products under CSA must submit complete test reports from an accredited laboratory and include a declaration of compliance to all normative clauses of the standard, including any national deviations (if applicable).
Frequently Asked Questions
Q: What is the relationship between IEC 11694-5-18 and ISO/IEC 11694-5:2018?
A: IEC 11694-5-18 is a specific publication numbering used by the IEC for the same technical content as ISO/IEC 11694-5:2018. The Canadian adoption (CAN CSA ISO IEC 11694-5-18) also incorporates this identical text. Users can reference any of these identifiers for the same standard.
A: IEC 11694-5-18 is a specific publication numbering used by the IEC for the same technical content as ISO/IEC 11694-5:2018. The Canadian adoption (CAN CSA ISO IEC 11694-5-18) also incorporates this identical text. Users can reference any of these identifiers for the same standard.
Q: Can IEC 11694-5-18 cards be read by readers designed for earlier versions?
A: Yes, with limitations. The standard requires that readers must support at least the previous edition (2006) for reading, but writing may require additional conformance checks. The interchange header includes a format version field to enable backward-compatible handling.
A: Yes, with limitations. The standard requires that readers must support at least the previous edition (2006) for reading, but writing may require additional conformance checks. The interchange header includes a format version field to enable backward-compatible handling.
Q: What is the maximum data capacity achievable under this standard?
A: The theoretical capacity depends on the number of logical tracks and the characteristics of the optical recording layer. Typical implementations support between 2 MB and 16 MB per card side, with track counts ranging from 200 to 800. The standard does not specify a fixed capacity, but instead defines the formatting rules; the actual capacity is limited by the card’s physical properties (Part 1–3).
A: The theoretical capacity depends on the number of logical tracks and the characteristics of the optical recording layer. Typical implementations support between 2 MB and 16 MB per card side, with track counts ranging from 200 to 800. The standard does not specify a fixed capacity, but instead defines the formatting rules; the actual capacity is limited by the card’s physical properties (Part 1–3).
Q: Are there any security mechanisms defined in IEC 11694-5-18?
A: The standard focuses on interchange data format. Security features such as access control, encryption, and digital signatures are optional and can be layered on top of the defined file structure. For biometric security considerations, refer to ISO/IEC 11694-6.
A: The standard focuses on interchange data format. Security features such as access control, encryption, and digital signatures are optional and can be layered on top of the defined file structure. For biometric security considerations, refer to ISO/IEC 11694-6.
This article was prepared as a technical overview of IEC 11694-5-18 (2026 edition applicable) for informational purposes. Always refer to the official published standard for certification and compliance requirements.