# Introduction #

List of default keys presented as **examples** in NXP Application Notes, but which were used ad-litteram by vendors/system-integrators.


# Details #

The list below details the publicly known and available default keys (specified in various application notes as examples):

| **Default key** | **No. of known systems using it** | **List of those systems** | **Approx. no. of cards using it** | **Approx. % of cards from total Mifare Classic cards** |
|:----------------|:----------------------------------|:--------------------------|:----------------------------------|:-------------------------------------------------------|
| ffffffffffff | 1 | SKGT<br> <table><thead><th> ? </th><th> ? </th></thead><tbody>
<tr><td> a0a1a2a3a4a5 </td><td> 1 </td><td> SKGT<br> </td><td> ? </td><td> ? </td></tr>
<tr><td> b0b1b2b3b4b5 </td><td> ? </td><td> ? </td><td> ? </td><td> ? </td></tr>
<tr><td> 000000000000 </td><td> ? </td><td> ? </td><td> ? </td><td> ? </td></tr>
<tr><td> 4d3a99c351dd </td><td> ? </td><td> ? </td><td> ? </td><td> ? </td></tr>
<tr><td> 1a982c7e459a </td><td> ? </td><td> ? </td><td> ? </td><td> ? </td></tr>
<tr><td> d3f7d3f7d3f7 </td><td> ? </td><td> ? </td><td> ? </td><td> ? </td></tr>
<tr><td> aabbccddeeff </td><td> ? </td><td> ? </td><td> ? </td><td> ? </td></tr></tbody></table>

As in the case of GSM COMP128, the example details from specifications/appnotes were taken ad-litteram, posing a security threat on the system.