How to se 'Require strong password in ASP.NET Identity'

Open your IdentityConfig.cs class, then modify your code as shown below

manager.PasswordValidator = new PasswordValidator
{
    RequiredLength = 6, // Minimum length of the password
    RequireNonLetterOrDigit = true, // Must include a special character
    RequireDigit = true, // Must include a number
    RequireLowercase = true, // Must include a lowercase character
    RequireUppercase = true // Must include an uppercase character
};

Use the PasswordValidator properties to define your own password validation policy