encrypted.cs

class Encrypted<T>
{
    readonly byte[] value;
    T decrypted;

    public Encrypted(byte[] value)
    {
        this.value = value;
    }

    public T Value
    {
        get
        {
            if (ReferenceEquals(decrypted, default(T)))
            {
                decrypted = DecryptValue();
            }
            return decrypted;
        }
    }

    static T DecryptValue()
    {
        return default(T);
    }

    public static implicit operator T(Encrypted<T> value)
    {
        return value.Value;
    }
}