https://learn.microsoft.com/en-us/dotnet/api/system.web.ui.page.enableviewstatemac?view=netframework-4.8.1&redirectedfrom=MSDN
Page.EnableViewStateMac Property (System.Web.UI) | Microsoft Learn
Gets or sets a value indicating whether ASP.NET should check message authentication codes (MAC) in the page's view state when the page is posted back from the...
property systemweb uimicrosoftlearn
https://24x7aspnet.blogspot.com/2009/10/enableviewstatemac-in-aspx-page-aspnet.html
EnableViewStateMac in an ASPX Page ASP.Net
Setting EnableViewStateMac=true is a security measure that allows ASP.NET to ensure that the viewstate for a page has not been tampered with...
aspx