Make CheckBox for Dictionary in ASP.NET MVC

I display each faculty with bound specializations:

@model Dictionary<Models.Faculty, IEnumerable<Models.Specialization>>

@using (Html.BeginForm())
{
    @Html.AntiForgeryToken()
    <div class="form-group">
        @foreach (var faculty in Model)
        {
            <section class="faculty">
                <header>
                    @faculty.Key.Name
                </header>
                @foreach (var specialization in faculty.Value)
                {
                    <div class="checkbox">
                        <label>
                            @Html.CheckBox(What should I add HERE) <b>@specialization.Name</b> (@specialization.Description)
                        </label>
                    </div>
                }
            </section>
        }
    </div>    
}

I want to get IEnumerable of specialization.specializationId in my Controller. I cant use @Html.CheckBoxFor(), couse my model is Dictionary. How Can I do this?