Machine Identification Code (MIC)
Definition
A pattern of tiny yellow dots (or equivalent steganographic marks) embedded in the output of many colour laser printers, encoding the printer serial number and print date-time; documented by the EFF since 2005.
- Also known as
- Extended Forensic Features (EFF) or tracking dots
- What they encode
- Printer serial number and print date-time
- Documented since
- 2005 (by the Electronic Frontier Foundation)
Common questions
What are machine-identification codes and why do they matter in document forensics?+
Machine-identification codes (MICs) are tiny yellow dots or similar steganographic marks embedded in the output of color laser printers and photocopiers. They encode the printer's serial number and the exact date-time the document was printed, making them valuable for tracing printed evidence back to a specific device.
How can you spot MICs on a document?+
The dots are typically yellow and very small, arranged across the page. You may need to examine the document closely or under magnification to see them clearly. They appear on most color laser printer and photocopier outputs.
Are MICs reliable for identifying the source printer?+
Yes. Because each MIC encodes a unique printer serial number and timestamp, they provide a direct link between a document and the machine that produced it. This can be critical for establishing when and where a document was created.
Related terms
- Banding
- Horizontal density variations across a laser or inkjet printed page, arising from developer roller irregularities, drum charging variation, or drive-train gear-skip; measurable...
- Daisy Wheel
- A circular print element with flexible plastic spokes each bearing a character, used in electronic daisy-wheel typewriters and printers from the late...
- Drum Period
- The repeat interval of a drum-surface defect in the printed output, equal to the drum's circumference; measured in millimetres to identify the...
- Dye-Sublimation Printer
- A printer that transfers dye from a donor ribbon to a receiver layer under heat, producing continuous-tone gradients; used for ID card...
- Electrophotographic Process
- The multi-step printing process used in laser and LED printers: corona charging, laser/LED exposure, toner development, transfer, fusing, and drum cleaning; defects...
- FICN
- Fake Indian Currency Notes. Counterfeiting and trafficking attracts UAPA 1967 Sections 15 to 17 (as a terrorist act when high-quality and large-scale)...
- Fourier Banding Analysis
- A signal-processing technique applied to high-resolution scans of laser-printed pages to extract the periodic frequency and amplitude of banding artefacts, used to...
- Golf Ball (IBM Selectric)
- Spherical typeball developed by IBM in 1961; rotates and tilts to bring the chosen character to the print position. Class link to...
- Intaglio Printing
- A high-pressure printing process in which ink is forced into engraved recesses in a steel plate and transferred to paper, producing a...
- Optically Variable Ink (OVI)
- An ink containing thin-film interference flakes (metal + dielectric layers, manufactured by SICPA and others) that produce a visible colour shift with...
- Piezoelectric Inkjet
- An inkjet drop-formation mechanism using a piezoelectric crystal to deform and eject a droplet without heating; used in Epson PrecisionCore and Micro...
- Ribbon Impression
- Inked impression made through a fabric or carbon-film ribbon on a typewriter. Carbon-film ribbons yield sharper, single-use impressions that allow text recovery...
Explained in these topics
- Printer Identification: Inkjet, Laser, Dot-Matrix, Yellow-DotA pattern of tiny yellow dots (or equivalent steganographic marks) embedded in the output of many colour laser printers, encoding the printer serial number and...
- Typescripts, Printed Matter, Currency and Mechanical ImpressionsYellow tracking dots embedded by most colour laser printers and photocopiers that encode printer serial number and date-time stamp. Also called Extended Forens...