Have the identifier in a table row

Hello,

I'm developing a web application that contains a list with multiple elements. My idea is that after clicking on one of the elements, it opens a new page with the details of the element clicked. For this, at the moment, I have to put something that identifies me the element: <div class="elem" data-id="2"> .

At this point, the lines in my list are being placed as follows (I'm using .NET MVC):

@foreach (KnowAcquisitionParticipant participant in Model.Participants)
{
    <div class="famo-row famo-body-row" data-is-new-participant="no" data-id="@participant.Employee.ID">
        <div class="famo-cell famo-col-1">
            <select class="famo-input famo-text-10" name="participantID">
                <option value=""></option>
                @foreach (Employee employee in Model.Employees)
                {
                    <option value="@employee.ID" @(employee.ID == participant.Employee.ID ? "selected" : string.Empty)>@employee.Name</option>
                }
            </select>
        </div>
        <div class="famo-cell famo-col-2">
            <input type="text" class="famo-input famo-text-10" name="totalHours" value="@(participant.TotalHours.HasValue ? participant.TotalHours.Value.ToString() : string.Empty)" />
        </div>
        <div class="famo-cell famo-col-3">
            <input type="text" class="famo-input famo-text-10" name="activeHours" value="@(participant.ActiveHours.HasValue ? participant.ActiveHours.Value.ToString() : string.Empty)" />
        </div>
        <div class="famo-cell famo-col-4 text-center">
            <button type="button" class="famo-button famo-cancel-button button-delete-participant">
                <span class="fa fa-trash"></span>
            </button>
        </div>
    </div>
}

However, I think someone can easily change the value of data-id and cause it to enter another page than the one supposed to be (I have a process that validates on the server whether the user has access or not).

I've been seeing other sites like Gmail or Outlook.com, and I do not seem to have any identifiers for the emails, and even when they seem to have it, I change it but always open the correct email.

How is it possible?