Query in tranformed collection fields

In collection transform i decrypt the encrypted field lastname

doc.lastname = CryptoJS.AES.decrypt(doc.lastname,secretKey).toString(CryptoJS.enc.Utf8);

This works and the html table shows the decrypted fieldname.

How would i find / query for (partitial) matches? Transform takes place after find. So People.find({lastname: ‘something’}) doesn´t work.

Info:The decryption needs to take place client side

Transforms are only applied when the data is being copied from a cursor to an object. So, if the cursor did not have too many rows, you could fetch() the data and perform the search on the resulting array.

thanks for the fast answer. I was hoping there is a better solution.