Thursday, May 31, 2018

Cookies, https and OpenId

I finally got around to looking at the various notices that have accumulated on the admin pages for this blog.  As a result:
  • This blog is supposed to display a notice regarding cookies if you access it from the EU.  I'm not sure that this notice is actually appearing when it should (I've sent feedback to try to clarify), but as far as I can tell blogspot is handling cookies for this blog just like any other.  I have not tried to explicitly change that behavior.
  • This blog has for some time used "redirect to https".  This means that if you try to access this blog via http://, it will be automatically changed to https://.  This shouldn't make any difference.  On the one hand, https has been around for many years, all browsers I know of handle it just fine and in any case this blog has been redirecting to https for a long time without incident.  On the other hand, this is a public blog, so there's no sensitive private information here.  It might maybe make a difference if you have to do some sort of login to leave comments, but I doubt it.
  • Blogger no longer supports OpenID.  I think this would only matter if I'd set up "trust these web sites" under the OpenId settings, but I didn't.
In other words, this should all be a whole lot of nothing, but I thought I'd let people know.

Friday, May 18, 2018

Bombshell revelations about Hedy Lamarr (sorry, couldn't resist)

A while ago I posted about the role of actor/inventor Hedy Lamarr in the development of the "frequency hopping" communication technology now used in cell phones, WiFi, Bluetooth and various military applications, among others.  Now (well, since last year) there's a whole movie about it: Bombshell: The Hedy Lamarr Story.  In fact, there's actually something of a cottage industry in Lamarr-related productions, including books, plays, magazine articles and not a few blog posts.

The movie goes into detail on Lamarr's life, from her childhood in Vienna to her Hollywood career, her relationship with aviation magnate Howard Hughes (who provided access to his company's chemists and engineers for her personal projects), her now-famous patent with George Antheil, her reclusive later days and her eventual recognition for her technical contributions.  There are fresh interviews with friends, admirers, children and grandchildren along with archival interviews of Lamarr herself, altogether providing a well-rounded view of a lively mind.

Bombshell and the Hedy Lamarr revival in general have given long-overdue appreciation to someone who until recently was most recognized for her work in an industry concerned nearly exclusively with her looks, despite her efforts to find more challenging roles and her ultimately unsuccessful attempts to break into producing.  My one quibble with the film concerns the impact of her patent.  Because geek.

It is clear that US Navy contractors used the patent directly in the development of a communication system among ships, planes and sonobuoys and that a related system was used during the naval blockade in the Cuban missile crisis.  At least some of that work was done before the patent expired, lending support to Lamarr's claim that she was due the customary payment for the use of her and Antheil's invention.

It's also clear that Antheil contributed significantly to the patent, particularly because he had experience in synchronizing player pianos.  The scheme used 88 frequencies, one for each key on a piano, and needed the ship's radio and the torpedo's to stay in sync.  Three guesses how this was accomplished.  Nonetheless, the initial idea of frequency hopping was Lamarr's and it was she who actively recruited Antheil for assistance with the practical design.

This was a real, significant contribution to communications, and one that was put to practical use, albeit not as originally designed, including in one of the most critical moments of the 20th century.  Neither was it a fluke.  Lamarr had a lifelong interest in what we now call STEM and this was not her only invention, just the most successful.  From what I've seen I have no doubt at all of her geek cred.

However, we should be careful not to go too far, as least not without providing a bit of perspective.  The film itself doesn't go so far as to say Lamarr invented WiFi.  That would simply not be accurate, though that hasn't stopped the occasional web site from making just that claim.  However, it does heavily imply that frequency hopping plays a major role in, for example, the security of military satellites, and it explicitly calls out WiFi, bluetooth and cell phones to claim that Lamarr's invention touches a huge swath of modern-day humanity.

Yes, but ... No one person invented WiFi, which includes everything from the use of the frequency spectrum to the handshaking and security protocols, an implementation of IP (internet protocol) and the specification of metadata such as the SSID.  Likewise, Lamarr's is not the only patent or invention concerning frequency hopping.  None other than Nikola Tesla filed an early patent describing it.  Wikipedia has a summary of other developments of the concept, including use by the German military in  World War I, well before Lamarr and Antheil's patent.

WiFi certainly doesn't use piano rolls to select frequencies.  Technology has marched on in the decades since then.  If we're going to credit the general concept of frequency hopping, we should recognize its full history, not just Lamarr's contribution.  Likewise for frequency hopping in the context of Bluetooth and CDMA in cell phones.

As to security, while the patent was originally filed for a "secret communication system", frequency hopping doesn't provide meaningful security against modern attackers.  Any real security is provided by encryption systems built on usual suspects like DES and RSA, which operate on completely different principles and were of course developed completely separately.  To see this, look no further than WiFi, whose original security was notoriously weak, even though it included both frequency hopping and an encryption layer on top of that.  Neither that layer nor the later improvements have anything to do with frequency hopping.

On the other hand, another of Lamarr's original motivations was to circumvent jamming -- flooding a frequency with enough noise to drown out any real communication.  Frequency hopping with a shared key -- the gist of the patent -- is still effective for that.  If you don't know which of several dozen frequencies the actual signal is on, you have jam all of them, which requires proportionately more power and might not even be practical in some situations.  That's very much alive, and important in military applications, but it's not a form of secrecy and it has little to do with WiFi or bluetooth, except that switching WiFi or Bluetooth frequencies can avoid accidental interference from other devices.

By all accounts Hedy Lamarr was an impressive person: talented, highly intelligent, diligent, creative and in many respects ahead of her times.  Bombshell does a fine job conveying this, and, probably more importantly, the often tragic tension between who she was and who most of the world wanted her to be.  It is also forthright about her flaws and failings and it even does a decent job with the technical details, even considering the critiques above.  All this is well worth recognizing and celebrating.  Putting Lamarr and Antheil's patent in proper perspective does nothing to diminish this, even if it takes away the easy narrative of Lamarr the unsung hero of the mobile revolution.