TEE is a joke. I don't even trust the newer SGX [1], which some blockchain companies like Corda [2] are adopting now, let alone TEE, with its myriad of security issues [3].

[1] - https://www.theregister.co.uk/2016/02/01/sgx_secure_until_yo...

[2] - https://www.corda.net/2017/06/corda-sgx-privacy-update/

[3] - https://invisiblethingslab.com/resources/bh09dc/Attacking%20...