> For the complete documentation index, see [llms.txt](https://docs.verifone.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.verifone.com/kld/key-information/key-import/how-to-import-ms-master-session-keys.md).

# How to Import MS (Master Session) Keys

### USB folders

* The Folder name is:

  * "MS/KEK" KEK (K0 usage) keys, 
  * "MS/KBPK" for KBPK (K1 usage) keys

  If no KEK keys, no need for MS/KEK folder and the same for KBPK keys

### Format rules

* File format can be TR-31 or Cryptogram.
* Entire file must be one format.
  * You cannot mix formats within a file.

### One key list per file

* Create a separate file for each master key list you want to send.
* Example:
  * If two KEK keys should be sent to a terminal:
    * Create two files under `MS/KEK`.
  * Same concept for `MS/KBPK` .

### Send behavior

* KLD picks one key from each file (top of file).
* KLD sends that key to the terminal.
* KLD deletes that key from the file.

See the naming rules in:

* [TR-31 File Formats (per folder / key type)](/kld/key-information/key-import/tr-31-file-formats-per-folder-key-type.md)


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.verifone.com/kld/key-information/key-import/how-to-import-ms-master-session-keys.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.