> For the complete documentation index, see [llms.txt](https://docs.hiveauth.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.hiveauth.com/has-for-wallets-pksa/proof-of-key.md).

# Proof of Key

A Proof of Key (PoK) process has been implemented to strengthen the security of the protocol and is used to validate the messages received by the **HAS** from the **PKSA**, but also to validate the data that is exchanged between the different nodes participating in the HiveAuth network.

Indeed, all the data exchanged between the **APP** and the **PKSA** are encrypted. Therefore, a **HAS** node has no way of knowing its content. However, to ensure that the data received has indeed been generated by the account associated with a request, the **HAS** will require the **PKSA** to also sign either arbitrary data or something that it knows.

A PoK is built by encrypting:

* the actual UNIX time when sending a `register_req` message
* the request `uuid` when replying to any request

The encryption is done using both the account's private key and the [Server Encryption Key](/has-for-wallets-pksa/server-encryption-key-retrieval.md). The **PKSA** can use any account key that is available to it (posting, active or memo) to perform the encryption.

The PoK will accompany each message sent by the **PKSA** to the **HAS**. The **HAS** will then:

* decode the PoK using its own private key
* ensure the message has been encrypted by the account by matching the public key retrieved from the encrypted PoK with the account public key retrieved from the blockchain.
* In the case of account registration, check that the provided UNIX time is within a 10 seconds boundary from its actual time. This check is performed to avoid malicious actors to reuse PoK they could have got their hands on.
* In the case of a request-related message, check that the decrypted `uuid` matches the `uuid` of the request.