Secure channels ( SCP80, SCP81, SCP03 and SCP03t )
The SM-SR communicates with the eUICC using a secure channel on interface ES5 – either SCP80 or SCP81.
In addition the SM-DP will establish an SCP03 or SCP03t secure channel ( ES8 ) which tunnels through the ES3 link between the SM-DP and SM-SR and through the secure ES5 channel between the SM-SR and eUICC.