ASP.Net Back button issue after logout

Hi I have this issue as I seen many before has had with the website allowing the suer to step back once logged out. I have seen this code below recommend to solve the problem, and it works. But my questions are, is this the best way of doing it? I dont want to cache any of the secure pages? Will the web app run slower with out cashing secure pages? Is there an alternative?

Response.Buffer = True  
Response.ExpiresAbsolute = Now().Subtract(New TimeSpan(1, 0, 0, 0)) 
Response.Expires = 0 
Response.CacheControl = "no-cache" 

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Thank you!