If I want to use kerberos instead of https (http over ssl) how do I make sure data is not tampered or read in the transit?
You have a false premise, but your question can be answered.
Encrypt the data. You can use secret-key encryption or public-key encryption (usually in conjunction with secret-key encryption - for non trivial amounts of data). Plus a secure method of key exchange.
Generally it is better to use a well tested solution (e.g. HTTPS or SSH) than try to create your own solution.
You're barking up the wrong tree. Kerberos is exclusively an authentication mechanism - it is as much use for the purposes you suggest as a banana.
Why do you want to use HTTPS?