restrict access to other users data by changing query parameter when using Data Driven Subscription

I have 7000+ users who will be sent links through email using Data Driven Subscription. TO differentiate user info, we pass a user specific data in the URL. We know that we can encrypt the user specific data like UserID (per say) in the URL and share encrypted data in the URLs sent to users.

I would like to know if there is any better way to restrict access to other users data, other than encrypting userID shared in the URL. I tried to use built-in UserID field while querying for user information but realized that it cannot be used along with data driven subscription.

Please suggest.

I am using Sql Server 2008 R2.