Magstripe campus cards have been used by colleges and universities for decades. They facilitate access to campus facilities and services via unique ID numbers and other small bits of identification data encoded on the stripe.

To do this, a magstripe contains tiny magnetic particles arranged in patterns to encode information. When swiped through a card reader, the encoded data is retrieved and processed to complete a transaction or grant access.

The data is encoded using a process called magnetic flux reversal, which allows electronic readers to interpret the information.

While magstripe campus cards have been a reliable option for decades, institutions have increasingly moved to more secure alternatives like contactless smart cards. This is because magstripes are vulnerable to wear and tear, skimming attacks, and cloning.

A survey by NACCU found that 95% of college and university card programs still included a magstripe on their campus card even though they had migrated to contactless technology for most or all functions.

Even with the migration to contactless technology, however, most campus IDs continue to include a magstripe. It can aid in a transition period as readers are replaced across the campus, support bank partnerships, and enable one-off custom applications to continue to function without the need for redevelopment.

History of the magstripe card

The cards were developed in the 1960s and rapidly became one of the most widely used technologies for storing and transmitting data in financial transactions, access control, and identification.

Initial development (1950s–1960s)

The concept of encoding data on magnetic media dates back to the early days of computing, but it wasn’t until 1969 when IBM engineer Forrest Parry invented the magnetic stripe card. He was working on a project to store digital information on a plastic card but struggled to securely attach a magnetic tape to it. His wife suggested using heat from an iron, which successfully bonded the stripe to the card. The rest is history.

Standardization and adoption (1970s–1980s)

• In the early 1970s, IBM worked with banks and government agencies to refine the technology.
• In the mid-1970s, the International Organization for Standardization (ISO) established standards for magstripe cards in its ISO 7811 document. It defined precise stripe placement, encoding methods, and data formats.
• Credit card companies, including American Express, Mastercard, and Visa, adopted magnetic stripe technology, replacing manual imprint systems.
• By the 1980s, magnetic stripe cards were widely used for ATM withdrawals, credit card transactions, and transportation fare collection systems.
• In the late 1980s, magstripe campus cards began appearing at colleges and universities.

Peak and decline (1990s–Present)

• In the 1990s, magnetic stripe cards became the global standard for payment and security. However, security concerns emerged as skimming and cloning fraud increased.
• In the 2000s, smart card technology – known as EMV chip cards – began replacing magnetic stripes for bank cards, due to its stronger encryption and authentication. The future of magstripe campus cards also came into question as contactless technology emerged as the more secure choice for student IDs.
• By the 2010s, many countries mandated EMV cards, reducing reliance on magstripe transactions.

Encoding a magstripe campus card

Magnetic stripe card encoding uses magnetic flux reversal to change the direction of magnetization within the particles embedded in the stripe. This lets digital data be encoded onto the card.

Magstripes are made up of tiny ferromagnetic particles that can be magnetized in different directions. When encoding data, a specialized writer applies a controlled magnetic field to change the orientation of these particles. A flux reversal occurs when the magnetic field switches polarity from north-to-south or south-to-north.

These reversals represent binary data, with each transition corresponding to a 1 and the absence of a transition representing a 0. It is the same binary data concept that forms the core of all digital systems.

When a magnetic stripe card is swiped through a reader, the read head detects these flux reversals, converts them into electrical signals, and then processes them as digital data. This enables the reader to determine the identification number or other data encoded on the stripe.

HiCo, LoCo, coercivity, and Oersteds

An Oersted (Oe) is a unit of measurement for magnetic field strength. In terms of magstripe campus cards, an Oersted defines the coercivity of the magnetic material, basically the amount of magnetic field strength required to change or erase the data encoded on the stripe.

Magnetic stripe cards are categorized based on their coercivity levels, which determine their resistance to accidental erasure and their durability in various environments

Low-coercivity cards (LoCo) have a coercivity level around 300 Oersteds. It takes a fairly low magnetic field to encode and erase data on these cards. They are easier to rewrite but are more vulnerable to demagnetization from external magnetic fields. Traditionally, LoCo cards have been used for hotel keycards, temporary access cards, and other short-term applications.

High-coercivity cards (HiCo) have a far higher coercivity around 4,000 Oersteds. These cards require a much stronger magnetic field to encode and erase data, making them more durable and resistant to accidental erasure. HiCo cards should always be used for magstripe campus cards.

Applying the magstripe to the plastic card

To apply magnetic stripes to cards, a thin layer of ferromagnetic material is applied to the card’s surface in a precise location.

To affix the stripe to the card, two methods are commonly used.

With hot-stamping, the magnetic stripe is heat-pressed onto the plastic card using an adhesive layer to ensure a strong bond. This is much the same way that magstripe inventor Forrest Parry’s wife suggested he do using the iron.

In the lamination method, the stripe is pre-applied to a sheet of plastic overlay material, which is later added to the cards during production.

The future of magstripe campus cards

In 2024, a survey by the NACCU campus card association found that 95% of college and university card program respondents still used a magstripe campus card. Many still included the magstripe even though they had migrated to contactless technology for most or all functions.

It is a testament to the resilience of this 50-year-old technology.

While it has been proven to be insecure for high-value transactions, it can still serve as a solid, cost-effective way to get an ID number into a system to identify a cardholder.