private static void SetListPermissions(SPList list, SPWeb web)
{
    try
    {
        list.BreakRoleInheritance(false);

        SPRoleDefinition readerRole = web.RoleDefinitions.GetByType(SPRoleType.Reader);

        SPUser allUser = web.AllUsers["NT Authority\\Authenticated Users"];

        SPRoleAssignment spRoleAssignment = new SPRoleAssignment(allUser);
        spRoleAssignment.RoleDefinitionBindings.Add(readerRole);

        list.RoleAssignments.Add(spRoleAssignment);
        list.Update();
    }

    catch (Exception ex)
    {
        //Log Exception
        throw;
    }
}