This enumerated value reports the encryption method (none, wep, tkip, aes, or aesTkip) currently used to secure this device's client-mode link to its access point. An admin verifies this to ensure the uplink connection is using the intended level of security rather than falling back to something weaker. For example, an uplink radio expected to use aes but instead reporting tkip would indicate the negotiated security level is weaker than intended, worth investigating on the upstream AP's configuration.