Does User App use cookies on the client browser?

What information is stored in cookies? If cookies are encrypted, what
method is used?

(If this differs by version of User app, that info would be very
interesting to understand, if not, assume latest greatest, say IDM 4.02,
UA Patch E or equiv of 4.02A.1 (HPD plus first patch). If 4.5 differs
that would be very interesting to know as well).