Can anyone recommend an encryption method for ALL user dbs using SQL Server 2016 STANDARD edition? Our clients are insisting that we now encrypt ALL their SQL Server data at rest, which must include tempdb. I think I have the following options available – 


Bitlocker entire drive(s)
TDE (but the cost of Enterprise edition breaks our support model for these clients!)
Always-Encrypted (but more a GDPR/Personal information solution, not for whole databases) – and cannot then “wildchar” search these fields, which is a requirement.
EFS the User databases location on disk
Some 3rd party application that does SQL Server encryption
Others?


Any recommendations appreciated (for SQL Server 2016 STANDARD edition only)
There are 3rd party tools which replicate TDE functionality.

I have tested the following during an exercise to evaluate whether we can move from Enterprise to Standard Edition:


https://www.database-encryption.com/
https://netlibsecurity.com/


In both cases, they seem to work by placing a driver between the SQL binaries and the storage layer, and after configuration are transparent to the connecting application. Queries work in the exact same way as for TDE-enabled databases. Once the data leaves the storage, it is unencrypted.  It would appear as an unencrypted database to all authenticated connections.

They do cost, but I believe there are trial versions available.

In performance tests (10,000 small insert queries into a clustered index) I found that DBDefence closely mirrored the performance of a TDE-enabled database. Query times for Netlib increased by approx 8%.  Obviously your specific scenario may differ.

All my tests were performed on SQL 2016 Standard.