* Question

When the master or slave host provides a long-term key to the link layer, the following three conditions may occur.

* Answer

When the master or slave host provides a long-term key (LTK) to the link layer—typically during Bluetooth Low Energy (BLE) secure communication—three possible conditions may occur:
LTK Matches and Authentication Succeeds
The provided LTK matches the one stored during the bonding process.
The link layer successfully completes encryption setup.
A secure connection is established, allowing encrypted communication between devices.
LTK Does Not Match or Is Invalid
The LTK provided is incorrect, corrupted, or doesn’t match the peer’s stored key.
The link layer fails to encrypt the connection.
The connection is either downgraded to an unencrypted state or terminated, depending on security policy.
LTK Is Not Provided or Not Available
The host does not provide an LTK (e.g., due to loss of bonding information).
The link layer cannot initiate encryption.
Re-pairing or re-authentication may be required to generate a new LTK for future secure connections.