Why are Custom object Name Field and date fields (Deterministic Encryption) not allowed to be encrypted?

Question

I read a lot of documentation regarding Shield Platform Encryption and I can't find any statement in regards to why some of these custom Object Name Field and date fields (Deterministic Encryption) are not allowed. Could you please advise me

Answer 1

why some of these custom Object Name Field and date fields (Deterministic Encryption) are not allowed.

The short answer is:

For Name - it is not
For Standard Date fields - not supported
For custom Date fields - supported, probabilistic only

One of the questions at the recent True to the Core Dreamforce session explicitly asked when fields of type Date (standard fields) and Picklist could be encrypted. The answer at the time was "we'll get back to you"

Under the covers, date fields show up a lot in filters for listviews and reports. Because encrypted fields can't be sorted, this would impose a burden on applications. Hypothesizing, the same could be true for name fields (which also can be auto-number that throws in a new wrinkle).

I've also heard that these issues can be better addressed if encryption were done closer to the hardware (SAN level).

Possible Workaround for the Name field

Start with using an autonumber field for the Name field and then use an external ID unique field for what you were putting in the Name field. The External Id field can be encrypted.

Possible workaround for standard Date fields

Use a trigger or automation to move (i.e. delete and copy) the value from a standard date field like Contact.Birthdate to an encrypted custom date field like Contact.Birthdate_PII__c