Your company’s data platform receives CSV file dumps containing booking and user profile data from upstream systems, which are stored in Cloud Storage. The data analyst team wants to join these datasets using the email field, which exists in both datasets. However, personally identifiable information (PII) like email addresses must not be exposed to the analysts. You are tasked with de-identifying the email field in both datasets before they are loaded into BigQuery, ensuring analysts can perform the join operation but cannot see the actual email values. What approach should you take?