It’s the day before Blackhat starts, and as usual a lot of my friends are en route to Las Vegas for some combination of Blackhat, Def Con, B-Sides, LobbyCon, or “just because”. Usually on this day I’d be in my car trying to reach “Ludicrous Speed” across the Mojave desert to join them, but I’m sad to say I’m not going to be attending this year.
Last year I skipped Vegas because I couldn’t afford to go; I was interviewing for jobs at the time having just watched my startup more or less implode. This year I’m avoiding it for two entirely different reasons – the minor reason is work-related, but the major reason is because I’m just not ready. While my transition has been going well and I have much love for the entire infosec community (you’ve all been *so* supportive – thanks, guys), I’m just not in a good place at the moment. My hormones have been out of whack for a little while leaving me a bit of an emotional mess, and I’m just not ready to deal with that many people with that many questions, no matter how well-meaning. Not a good environment for me right now.
I will miss you all intensely (I’m fighting back the tears as I type this) but this is a Good Decision. Next year I’ll re-evaluate and things may well be different, but for now this is what it is.
Putting all of that aside though, if you want to help tip the scales the other way next year then there is something you can do to help – send me a souvenir! Send me a shot glass or a mug or a cheesy blinky-LED pin or something, to:
1 Infinite Loop
Show me some love! Send me a thankyou for something I’ve done in the past, or an encouragement to do something new, or whatever. Make a girl smile – remind me of why I’m still in this business after ten years and help cheer me up while you’re at it. I could use it…
Figured it was time for another blog post, one that I’ve been thinking about for a while. I was complaining on Facebook about some of the negative side effects of estrogen therapy and started thinking about what the positive effects have been to counterbalance the negative – turns out there’s rather a lot, most of which I really didn’t expect.
I did a lot of research on estrogen before starting and I certainly knew what I was getting into; 2 years in I’m seeing many of the “expected” changes that were predicted although it’s likely to be a few more years before their effects are complete. My body fat has begun to redistribute (away from my belly and into my hips / thighs / breasts, with less-pronounced changes in my face), my muscle mass has decreased (I *really* can’t lift heavy things like I used to be able to), my skin is softer and my body hair is much finer and grows more slowly, my skin is less oily (with correspondingly less pimples), and my body odour has changed to be sweeter and less acrid.
These were all things that I expected – most any site on MtF hormones will tell you that these things will happen. However, there have also been *many* more changes that I really didn’t expect. In no particular order:
Sleeping: For my entire adult life I had severe sleeping problems, often lying awake until dawn despite being utterly exhausted – 2-3 hours a night was pretty commonplace for weeks or months at a time. Even sleeping pills wouldn’t work – Ambien did nothing at all, melatonin would occasionally help (but not often), and nothing else short of an anaesthetic had any effect at all. The day I started estrogen and progesterone though I slept like a baby, and have ever since. In fact, I used to be able to tell when my progesterone was running out by gauging my sleep patterns – if I slept badly for 2-3 nights in a row I’d check the calendar and it would be 6 weeks on-the-dot since my last progesterone shot. I now get a progesterone shot every month, and have never slept so well.
Dreaming: Pre-hormones I could count on my fingers the number of dreams I’d had in my entire life. At one point my wife bought me a Zeo sleep monitor and I remember being utterly thrilled when I dreamed one night while wearing it – my excitement at having an EEG recording of an actual dream was practically uncontrollable. Nowadays though I have several vivid dreams every night, slowing down somewhat towards the end of my estrogen cycle – it took some getting used to but nowadays it feels strange when I don’t dream the entire night away.
Depression: As is common with transgendered folks, I suffered severe depression for many years, at one point even going on Prozac (which screwed me up in all kinds of ways but didn’t actually help in the slightest). I remember feeling different after my first dose of hormones though – it took me a full week to figure out that what I was feeling was my depression not being there. I feel like my emotional range has drastically shifted towards the positive; while I still get depressed from time to time it’s no longer my de facto state-of-being and I’m definitely happy-dominant nowadays
PMS: This is my wife’s name for what I go through towards the end of my 3-month estrogen cycle, when my levels are starting to drop. I get irritable, moody, prone to mood swings, I cry for no reason and get general-purpose cranky-bitchy for about a month – then I get my new hormone pellets and I’m back to my usual self again. Believe me when I say that chocolate works very differently for women than it does for men – pre-hormones I enjoyed the taste of chocolate but nothing more, while nowadays it really helps to stabilise me when I’m PMS’ing. The difference is stunning.
Hot flashes: Another end-of-cycle effect, although this one comes a couple of weeks after the PMS starts. My wife has always been more prone to cold while I’m more easily overheated, but these come and go pretty rapidly (usually only minutes at a time). I’m told it’s very similar to when menopausal women get hot flashes – biochemically there’s some very similar things going on so it kinda makes sense.
Skin pH: Probably the root cause of my body-smell change (and possibly related to the skin oil decrease), the change in my skin pH has also caused other effects. Perfumes smell very different on me now – scents I used to wear just don’t smell right any more and I’ve had to find new perfumes to replace them. More dramatic though has been the effect on my silver jewelry – silver used to corrode very rapidly against my skin (silver rings would turn almost black within days) but nowadays silver stays nice and bright more or less indefinitely.
Dry hair: Also related to the decrease in skin oils is a change to my hair. My hair is much less greasy, to the point where I have to be careful not to wash it too often – it just gets dry and brittle if I wash it too much. It soaks up conditioner like you wouldn’t believe and still feels dry, I’m still experimenting with “intensive” conditioners to see how they fare but they certainly help.
Sun effects: Two big changes here – firstly I burn way more easily than I used to. Last year I went for a walk with a friend of mine on a sunny day; not even an hour in the sun and I ended up blistered all over my shoulders – before hormones I would have been fine. That was the day I learned a new love and respect for sunblock! More recently I’ve noticed that I don’t really tan as much any more – I freckle! Never had freckles before but now I’m covered, and I get even more every time I step outside. I really like this one – freckles are cute!
Allergies: I never used to have problems with seasonal allergies, now I’m sniffling and sneezing all summer and have to take some pretty serious anti-histamines to keep it under control. Still don’t have a problem with my cats (yay!) but pollen is a killer, and I’m still trying to figure out what flowers I’m most allergic to – sometimes I can’t even be in the same room as a gorgeous bouquet, while other times I’m completely fine.
Taste and Smell: I don’t think that the things I like have changed (I still can’t stand mushrooms and still love vegetables) but my senses of smell and taste have definitely intensified. For example, I’m a lot pickier about what red wines I do and don’t like (because the difference between them is now much more pronounced), and I can actually enjoy the flavours of a nice salad instead of it being little more than just crunch.
Swollen feet & ankles: Especially towards the end of my hormone cycle, if I sit down for too long or drink too much my feet and ankles will swell noticeably, sometimes to the point where I can’t get my shoes on! Not a problem that I ever had pre-hormones, and not honestly that much of a problem nowadays – definitely a new experience though…
Pain threshold: My pain threshold has dropped considerably since starting hormones. I remember when I was a kid I had an ingrown toenail that my doctor just couldn’t get rid of; more than once I cut into my nail bed to dig it out myself since it was simply more expedient than a doctors visit and the pain really didn’t bother me. Not so nowadays – my tolerance for pain seems much more “normal” but again, that took some getting used to.
Girlbrain: Kind of hard to explain, but my brain seems to just work differently nowadays. Where I used to remember things very literally (often with perfect word-for-word recall of conversations), my memories are now much more emotional – I may not remember exactly what was said but can perfectly recall how it made me feel. I’m much quicker to trust people and much more free with my emotions, I have much more clarity of myself and others, I have infinitely more self-confidence – and all of that manifests in a million different ways. I’m able to make friends in a way that I never have before, able to find joy in the little things in life, able to just be happy. I feel like I’ve shed all of the lies and fakeness that came with being a woman’s brain trapped in a man’s body (and doing a bad job of pretending to be the latter) – now that my brain and body and outward appearance are in sync, the grey matter up top is just that much more effective. Boybrain just seems broken in comparison.
Nesting: Another odd one to describe, kind of related to girlbrain – I nest! I love making places my own, whether it’s the desktop on my computer, my desk at work, my bedroom, kitchen or anywhere else – if it’s my space then I make it mine. I clean, I tidy, and I enjoy doing it; I arrange and rearrange and move and fiddle until it feels just right – I nest
“Is it all worthwhile” is an easy question to answer – despite all of the complexity and newness (I feel like I’m going through puberty again) it’s absolutely worth it. Even if all I had gotten from hormones was sleeping right and freeing myself from depression it would be worth all of the side-effects – and I’ve gotten so much more than that. I really like girlbrain, nesting is really a lot of fun, and I even love my freckles! Estrogen – it’s not for everyone, but for me it’s the best drug in the world
Wow, has it really been over a year since I wrote anything here? That sucks. I’ve been thinking recently that I really should start blogging again but my job kinda nixes writing anything publicly about technical matters; I’ve been waiting for something good to come along that was worth writing about and which wasn’t going to get me in trouble. I think I finally found something
Spoiler alert: This post is going to be very personal and not at all technical. I may actually open up comments for the first time in *forever* when I’m done though, so stay tuned.
Yesterday was my Rebirthday – the second anniversary of the day I that I finally made up my mind to transition permanently. I really don’t feel like the same person who made that decision; my world has changed so much since that day and I really do feel like I’ve become an entirely new person. I’m actually quite proud of this shiny new me and it feels like a story that I need to tell – this celebration seems like a good reason to do that, and hopefully it’ll spur me into writing more about transexualism and all it involves. Perhaps someone, somewhere will find something positive in my experience that makes their own journey a little easier, and if not then I guess all you cisgendered folks will just learn a little more about what us trans folks go through on our journeys of self-discovery.
The scene: it’s May 21st 2011, and my wife and I are about to get on a plane to Las Vegas. We’ve bought ourselves tickets to go and see Kylie Minogue at Caesar’s Palace on the last night of her US tour, so a long weekend of fun awaits us. This time things are different though – I’m dressed as a woman, and I’m about to go through my first female TSA patdown.
I had been flirting with changing my gender for about a year and a half, essentially waking up every day and deciding what gender to present for that day. Since I was self-employed I had a lot of flexibility; if I had important meetings that day I would usually present male (so as not to freak anyone out), but otherwise I’d probably present as a woman. I’d go back and forth as necessity dictated, terrified that the sky would fall down on me if I made the wrong choice – dressing as a woman had certainly led to some unexpected encounters (my landlord was a little surprised when he stopped by one day) but I had never had a problem. It had taken me the better part of a decade to sufficiently come to terms with my own gender that I could leave the house dressed as a woman, and I’d found a certain level of comfort in doing so.
That day was different though. I don’t like going through TSA at the best of times (it’s *far* too invasive for my taste) and this time I had no fallback plan – I had decided to present as a woman for the entire trip and had no male clothes with me at all. I was *way* out of my comfort zone, utterly terrified, and yet oddly comforted at the same time – I was, after all, just being myself. I had familiarised myself with the appropriate TSA regulations, I had a lawyer from ACLU on speed-dial in case anything did go wrong, and I was all set for a trip to Vegas.
I have never been so scared in all my life as I was going through that security checkpoint. I kept running through nightmare scenarios in my head, playing out how things could go, trying to plan for every possible eventuality. And then it was over in the blink of an eye, completely uneventful. Nothing happened, and before I knew it we were on the plane and headed to Vegas (still shaking from fear, but otherwise unharmed).
The trip itself was amazing. We got our makeup professionally done before the concert, I got to wear one of my favourite party dresses, Kylie was her usual dazzling self, and the concert was everything we hoped it would be. We gambled, we drank, we partied, and I did it all in dresses and skirts and high heels and makeup and all the trimmings (as Vegas demands!). The trip home was marginally less scary (I’d done it once so it wasn’t as terrifying) and before I knew it it was all over.
It was a day or two after the trip that it really sank in what had happened. I had gone through one of the most terrifying things I could possibly imagine, and not only had TSA been no big deal but I’d ended up *really* glad I had chosen that path for that trip – being myself for those few days had been completely comforting and enjoyable. I’d had a *fabulous* time, and there had been no negative repercussions whatsoever. I quickly realised three things:
1: Whenever I felt like I had a choice, I was choosing to be a woman.
2: Whenever I felt like I *had* to be male it upset me immensely – I truly hated it.
3: If I could cope with TSA as a woman, I could cope with anything.
I finally realised that the only impediment to permanently changing my gender was my own fear, and I also realised that that fear was completely unfounded. I had made my mind up – I was going to stay a woman for the rest of my days, and that I really was able to deal with the world as a woman. A month later I had one of my first surgeries to make that life a little easier, and a month after that I started hormones. My life had finally begun.
Two years on, I fell like that scared little girl is finally (mostly) gone. Estrogen has changed both my brain and my body in so many ways, both expected and unexpected (that’s another post entirely) but almost all good; transition has had very few downsides for me. The worst is that I now get PMS (as my wife calls it) – I’m on a 3-month Estrogen cycle and for the last month of that (when my levels are starting to drop) I get super bitchy, easily upset, and generally a little unstable. Most women are like this for a week every month; I’m like it for a month every 3 months. It occurs to me that when that’s the worst thing I can point to about my life it’s really been a good move for me – it’s really not much of a downside.
On the other hand, I’ve found a level of inner peace and self-acceptance that I never even knew existed. I understand myself, I understand other people, and the world is just so much easier to live in nowadays – I’ve made some *amazing* friends (something I was never really able to do as a man) and I can look myself in the mirror every day and truthfully say that *I like my life* – that’s a really big deal when you’ve spent 33 years in deep depression. Most of the people I see on a daily basis never knew Chris and completely accept me as Kristin; looking back it feels like I never really was Chris, I was just Kristin pretending to be a boy and doing a lousy job of it. I sleep at night. I don’t get random fits of anger and frustration and hatred at the entire world for making me the way I am – I’ve found myself, and I’m finally happy.
One sad part about all of this is my family. I’ve really enjoyed re-meeting people and getting to know them all over again, and I’ve not had the chance to do that with my family yet – and I probably never will with my parents. I’ll never forget when I came out to them and my father asked if it meant I was “going to start sniffing bicycle saddles”, as if transexualism was synonymous with the most deviant sexual fetishism that humankind can conjure; likewise I’ll never forget when my mother (after encouraging me to wear what I wanted when I was visiting) scolded me for going to get something from my car while wearing a skirt, because “What if the neighbours see?”. They instilled in me a shame and self-loathing that took me a very long time to get over and made me alienate much of the rest of my family along the way (after equating them with the same viewpoint); after they found out the truth and I found out that most of them are actually wonderful, caring people who really don’t see a problem I’ve been trying to rebuild some bridges. It’s hard to keep in touch when you’re a continent away but Facebook helps a lot, and I’m looking forward to getting an opportunity to see them again soon. I miss having parents but it’s taken me a long, long time to get over the way they made me feel about myself, and I don’t know that I can cope yet with re-introducing that into my life. Some day, perhaps, but not today.
It’s hard to think of a “best thing” that’s come out of this for me – there are so many. I love finally being able to dress the way I want to, I love wearing makeup (I like to think I’m pretty good with it by now), I love understanding myself and being able to have true, close friends. I love being able to interact with the world in a way that actually makes sense to me, and have the world interact with me in similar fashion; I love seeing the effect that my vanishing depression has had on my wife as her constant worrying about me lifts and eases. I love my life, I love my friends, and while (of course) there’s still things I would change, I’ve finally found a place in this world that I’m happy with.
So hi. I’m Kristin, a 2-year-old woman. Would you like to be friends?
In the absence of an “official” download link for these so far (although I’m sure they’ll be up on the Shmoocon page soon enough), my slides from Shmoocon this year. Seems it got a little press coverage and a whole bunch of attention on Twitter, so I figured I should get these out ASAP.
Hopefully video will be up soon but if anyone has questions about the talk in the meantime please ping me (ideally on twitter) and I’ll update the FAQ as and when I can.
What hardware / software were you using?
I used a Vivopay 4500 contactless card reader, an MSE-750 magstripe reader/writer, a Square dongle for my cellphone (on Android, not iPhone), and some code I wrote based on 3ricj‘s PwnPass code (no longer publicly available, afaik).
How did you get magstripe data from a contactless read?
The contactless reader spits out magstripe-formatted data as its intended mode of operation. I get valid Track1 / Track2 info (lacking only the name, which is usually “Valued Cardmember” or some such), which I just copy and paste to T1 / T2 on the MSR. There’s really not much to it – and yes, I’m processing credit card transactions without knowing the cardholder’s name.
Can you use the resultant card data online?
I get a valid cardnumber and expiry date (both usually the same as printed on the face of the card) and a single-use CVV value. If you can find somewhere online that’ll let you process a transaction with nothing but a card number and expiry date then yes you could, but otherwise you’re restricted to writing a magstripe and using that.
This is old news – XYZ did this years ago
I’m certainly not the first person to demo RFID vulnerabilities in payment cards. I haven’t heard of a full end-to-end demo before (RFID -> magstripe -> Square -> Profit!) but that doesn’t mean it’s not been done; I won’t be the last either as long as the industry keeps denying the problems. Now that it’s been irrefutably proven live on-stage that contactless fraud is possible I’m hoping that some of these issues can be addressed; if not don’t expect me to be the last person to talk about it either.
So what’s the deal with the CVV?
Credit cards have 3 CVV codes, one printed on the back of the card, a second encoded onto the magstripe, and a third from the RFID which changes with each read. Square (as well as some other combinations of PoS terminal + backend processor) is unable to tell the difference between an RFID transaction and a magstripe transaction, so as long as the CVV is valid (i.e. it’s being played back in-sequence with no repeats) the transaction goes through.
I haven’t posted here in a while since most of what I’ve been working on must stay secret for the moment, however I tweeted a couple of things today that I think really deserve a fuller explanation. This post is deeply personal and not at all security-related so if you’re only here for the infosec stop reading now; if you’re still here let’s start with what I tweeted and go from there.
1/2 I now meet all requirements to change my legal gender in the state/country where I live (California, USA) and the country I’m from (UK).
2/2 If I did so, none of the three would allow my happy seven-year-old marriage to continue. I am required to divorce my wife first #crying
Where to start?
I started getting curious about the first point coming back from a doctors visit today. I had just ticked “F” on a form for the first time and was idly wondering when I could change my drivers license. As it turns out it takes a doctor to attest that both my “gender identification” and my “demeanour” are female; that gets me a court order (the same court order as my name change if desired) and everything goes from there. My green card is slightly different, in this case I must get my doctor to attest that I have “undergone clinical treatment” to become female; I actually now have several doctors who could complete this for me despite the short list of accepted specialties. The UK requires me to live as female for 2 years before I “qualify”, however they would likely defer to my US transition and grant it based on that alone.
This came as a real surprise to me. The idea of changing all my legal documents really snuck up on me – I remember reading about it all a while ago and thinking that it was a while before I’d have to worry about it; as it turns out “a while” has passed. This would have made me ecstatically happy if it weren’t for the second part of this.
In the UK there is one additional requirement before they will recognise my gender transition: I must provide the “gender recognition panel” with a copy of my divorce decree. You read that right, I am compelled to divorce my wife of almost 7 years before I can change the “M” to an “F” on my passport. California isn’t even that explicit – proposition 8 simply says “Only marriage between a man and a woman is valid or recognized in California”. If I change my drivers license then it’s simply *poof*, my marriage isn’t valid any more. Federally I’m no better off; if I chose to drive across the country my marriage would go from valid to invalid several times along the journey – I guess the same thing happens at high speed when I get on a plane, and I don’t even want to know what the consequences are to any contracts that my wife and I sign given the complexities of where companies are “based” nowadays.
Nobody should ever have to feel like this. I’m upset that the government is forcing me to choose between my gender identity and my marriage; the “Defense Of Marriage Act” is a joke. I’m ashamed of my country, both the one I’m originally from and the one where I currently live – and I’m especially ashamed of California for passing Proposition 8. I’m angry that this is all driven by people’s hatred of each other; some crazy religious folks decided that the brightly-dressed people at Pride shouldn’t be treated the same as everyone else and suddenly my marriage is invalidated against my (and my wife’s) wishes. I’m confused as to how the world could have gotten so broken without anyone noticing, and I’m so very, very sad for everyone else who’s caught up in this ridiculousness.
Somewhere, deep underneath it all, I’m still ecstatically happy that I’ve reached this milestone. It’s been a long time coming and I’m *really* looking forward to being my sparkly-pretty shiny new self for Blackhat and Defcon this year; on a wider perspective I see gay marriage legalising in New York and it gives me hope for humanity after all.
Isn’t it time we fixed this?
I’ve got one major complaint about my Samsung Vibrant that I’ve not yet found a solution for – the headphones are way too quiet. When I tried to watch Avatar on a flight home a few days ago I couldn’t hear a single word that was said despite full volume on two completely different headsets. I gave up pretty quickly, it really wasn’t worth the effort.
When I got home a quick bit of googling led me to this post about a volume fix for the i7500. My Vibrant is an i9000 but the code to access the engineering menu (*#197328640# in Dialer) worked just the same – I’m assuming it’s standard across all recent Samsungs, not just the Galaxy S series.
There’s all manner of goodies in there; I’ve yet to find a fix for my volume issue despite all manner of apparently volume-related controls. I did find some other great stuff though, a quick summary:
Menu 1,8,7,2,2,1 should be “WCDMA ALL” – choosing this will disable 2G network access entirely. I’ve verified that it does indeed disable 2G but I’ve not verified how much of the phone still works afterwards – be careful with this one! Menu 1,8,7,2,1 to reset back to 2G and 3G combined, should be “Automatic”.
Menu 1,8,3,1 displays the current ciphering status, i.e. whether or not your current call is currently encrypted.
Menu 1,8,8 is called “Auto Answer”. While this looks like fun I couldn’t get it to work; I expect you can do the same with an Android application anyway.
Menu 1,8,7,7 is “IMSI replacement”. The IMSI is the equivalent of a username in GSM, so replacing it is a potentially bad thing to do. I didn’t mess with this since I didn’t have a BTS to hand at the time; next time I bring one online I’ll check it out.
Menu 6,2,3 is “PCM Logging”, I’m assuming that PCM means “Pulse Code Modulation“, i.e. the audio path. I managed to enable this one but couldn’t find any recordings, I’m guessing it’s either going to a “special” directory that I don’t have (and therefore it’s failing) or it’s going down a debug port.
Speaking of debug ports, menu 6,4 is “Diag Config” with various settings for debug logs via USB, UART, or IPC, with interesting settings like “Ramdump On/Off”.
For the GSM hackers: menu 1,4 gives your closest 6 UMTS PSCs and RSCPs or your closest 6 2G ARFCNs (with signal strength) while menu 1,1 gives you the current Band, MCC/MNC, RSSI, CellID and LAC.
Menu 1,8,2 is worth it’s own mention – apparently “FAKE SECURITY” is “Not support” (screenshot )
Offtopic: If you want to disable 2G on your Motorola Droid you can do so by first accessing the Programming Menu: ##PROGRAM in Dialer and hit send, the password is 000000. Select “08 Test Mode”, click Enabled, Next, Next, and set “Network Mode” to EvDo only. I’ve actually verified that this does break the phone though (cannot send SMS or make calls) so you might not want to do that. ultramegaman says that the “SPC password” doesn’t work on the Motorola Milestone – I’m shocked that someone, somewhere thought that “000000″ wasn’t secure.
Finally, I started reverse-engineering the applet that displays that menu. I haven’t gotten much further than running apktool and dedexer across it thus far but already the failure is pretty epic. This is the top-level manifest file for the apk, i.e. the starting point for everything that the .apk does (if you see a blank page view source or try another browser – Firefox works, Chrome doesn’t) and scroll down a couple pages. Pretty soon you’ll see:
<data android:scheme="android_secret_code" android:host="197328640"/>
which is, of course, the “secret code” that gets you into the engineering menu. That’s not all though, there’s pages and pages of them – 41 secret codes in all by my count. I’ve no idea what they all do (although many seem to be replicas of each other) but there’s certainly some fun to be had poking around it all.
$50 goes to the first person to tell me how to make my headphones louder – I just don’t have the time to sit down and tweak every control and then reboot to see if it works. $100 goes to the first person that gives me a desktop widget to switch between 2G, 3G, or auto – there’s other things I should probably be working on before reverse-engineering Android apps If it turns out that either one gets done by me (presumably because I find some spare time) then the EFF can have the winnings…
Slides (OpenOffice) from my Defcon talk – hopefully video will be coming soon as well.
A few notes about the demo and results.
Firstly, power output. I was transmitting a total of 25 milliwatts – for a point of comparison that’s about as much power as a typical LED while a small flashlight consumes over a hundred times more. My antennas have 13dBi forward gain, giving me an EIRP of half a watt. That’s really not much power at all; I’ve heard from several people that the signal couldn’t be picked up at the back of the room. This was deliberate – I kept the effective range as small as possible to limit the chance of catching a cellphone whose owner hadn’t been informed about the demo. I suspect that many, many more handsets would have connected if I’d used even marginally more power.
During the talk at least 30 handsets connected to my tower; there were probably many more than this but the logs were all destroyed on-stage (I broke the USB key into several pieces – last I heard Agent X had the remains). Logged data included IMSI, IMEI, all numbers that were dialed, and of course audio recordings of all calls made (a total of 17 calls were connected during the talk). I don’t know how many calls were attempted; it’s possible that many more people may have heard the warning and hung up before Asterisk tried to connect the call. I’ve not heard from anyone that they saw any kind of warning on their handsets despite the lack of encryption on my network.
A couple of defenses: AT&T apparently have a service offering voice & SMS encryption, I can’t find much more info on it and it’s reportedly only available to business and government users. I’d very much like to see it deployed more widely; it’s a good approach to the security problems in GSM (assuming it works as stated). Blackberry is another good option – they add a second layer of crypto for data (not sure if it adds anything for voice) and I’ve been told they have a setting to disable 2G. This is a Very Good Thing; I’d love to see someone add this setting to Android as well if it’s at all possible. In the medium to long term GSM simply needs to be turned off; it’d be more work to fix it than it would be to upgrade (given that 3G/3.5G/3.9G/4G are all available, are being deployed now, and offer far superior security).
Some points about the legal shenanigans that surrounded this talk. I never heard first-hand that AT&T were planning to sue; the rumour certainly came to me from a credible source (meaning I had to take it seriously) but I’m very glad it turned out to be incorrect. I’d like to thank the FCC for taking the time to talk to me on such short notice; while it certainly would have been nice if they had expressed any kind of opinion about the demo I at least appreciated the opportunity to hear their concerns about the talk and explain the mitigations that had been put in place. Talking to the feds in advance of such a big event is always a great option, and I was glad to have the opportunity to do so here.
Finally, I’d like to say a really big thankyou to the EFF; without their assistance the talk would not have gone ahead (the demo certainly wouldn’t have). If you want to see more work like mine at more venues like Defcon, go ahead and donate. They’re worth it
//edit: I also owe a big thankyou to the Goons (many of whom aren’t actually listed on that page). They did an absolutely superb job with helping me lug all my gear around, find places to set up and people to assist, and generally making everything go. Ply them with alcohol at every possible opportunity – they put in an amazing amount of effort at Defcon and really don’t get to enjoy the show much. Thanks, guys
Now that I’ve given the first of my Vegas talks I wanted to post everything online for anyone who couldn’t attend in person.
217 feet is the range I set; I believe that’s a world record (beating both the 69 feet from Flexilis at Defcon 13 and the 65 meters claimed by ThingMagic in a Google Tech Talk). My equipment is capable of far more but I hit the limit of my range; a chainlink fence a few hundred yards away was reflecting the RF power, meaning that more power led to greater interference and hence lower range. That 217 feet used just 10W of RF power; my current amp is rated at 70W and will probably deliver a hundred watts if it’s cranked right up – it should be plenty capable of 500+ feet reads.
I’m keen to demo this in-person while in Vegas; the demos at the talk are always constrained by the room (again, reflections from the chairs, the people, and the back wall of the room) so if someone can come up with a suitable place to test I’m happy to demo multi-hundred-feet reads. I suspect that the top of a building would be ideal; reflections from the ground should be directed outward and not pose a problem (it’s also worth noting that the commercial reader I started with has a lot less problem with reflections, however it’s not legal to just amplify the signal directly for reasons I discuss in the talk).
If anyone has ideas on how to set this up please get in touch; if all else fails I’ll try to get the folks from Guinness World Records to officially certify the read range, and/or set up a demo for press back in California at a later date.
Additionally I’m going to run an RFID read range competition at Defcon next year (details to come at Defcon). I had a huge amount of fun playing with this stuff, I learned a lot, and can think of about a thousand ways to improve on my own record. Think you can do better? Do it – and bring the results to Defcon next year!
Unfortunately, I’ve heard that AT&T may be considering suing me to stop my talk. I can’t understand why this would be the case, and I hope that if it’s true, they will contact me first to discuss their concerns.
Let me clarify some things about my talk. First, I’m not doing anything to AT&T’s or any other network. I’m just going to do a demonstration of my attack. It will not affect the 911 service. Nor will it interfere with anyone’s ability to call 911 unless you’re both in (or near) the demonstration room and also have a GSM phone. The demo will not affect people on Sprint or Verizon or any CDMA network. If you’re nowhere near the Riviera you won’t be affected.
So if you’re in the room, need to dial 911 and you have a GSM phone you can just raise your hand and shout. In the extremely unlikely situation that someone near the room with a GSM phone connects to my demo network and also needs to dial 911, I am taking the extra precaution of ensuring that that person will be connected to someone local who can call for or send help.
I wanted to be clear that the EFF haven’t just given me carte blanche here. I doubt they’ll ever say “Intercepting cellphone calls is perfectly fine as long as you do X Y and Z” – what I’ve done with their help is try to work out a way to minimize any legal risk associated with the demo, and to do it safely, so that I can show people an important problem with GSM. I wouldn’t say I have EFF’s “stamp of approval” on the demo, but they’ve certainly offered plenty of helpful advice and I’ve been trying to take all of it.
The EFF have also asked not to be involved in the data destruction. I’m open to suggestions for a trusted third-party to either destroy the logs generated during my demonstration or verify that they’re wiped.
Hopefully that’ll explain my talk to anyone with safety concerns and head off any unnecessary and unfortunate legal actions. I’m open to talking further with AT&T or anyone about this. Here’s hoping for no major hiccups…
I’m planning to give a pretty spectacular demonstration of cellphone insecurity at Defcon, where I will intercept the cellular phone calls of the audience without any action required on their part. As you can imagine, intercepting cellphone calls is a Very Big Deal so I wanted to announce at least some of the plan to reassure everyone of their privacy.
First and foremost – I’m not just making this stuff up. I know when to get advice from a good lawyer, and in this case I’m taking the advice of the very best there is: the EFF. They’ve been kind enough to offer their help and I’m taking it – this is what we’ve worked out.
1. If you’re in an area where your cellphone calls might be intercepted, there will be prominent warning signs about the demo including the time and date as well as a URL for more info. This will be the only time when unknown handsets will be allowed to connect; at all other times only pre-registered handsets will be granted access. You will be clearly warned that by using your cellphone during the demo you are consenting to the interception, and that you should turn your cellphone off during that time if you do not consent. A recorded message with essentially the same info will also be played whenever a call is made from the demo network.
2. The demo itself will be performed from a machine with no hard drive, only a USB key for local storage. At the end of the demo this USB key (including all logs, recordings, and other data) will be handed over to the EFF for destruction. No logs, recordings or other data will be exported from the machine except as necessary to connect calls during operation.
3. Transmit power will be kept to a maximum of 250mW (for comparison, a handset is typically 2W) and will comply with all relevant FCC regulations to operate in the band.
4. At all times, for all connected handsets, a best-effort will be made to connect calls successfully to their destination. It is unlikely that any 911 service can be provided, however a best effort will be made to connect any emergency calls to a suitable local destination.
Also, to be clear, my demonstration should not affect handsets on Verizon or Sprint in any way. The technology I’m working with is GSM and these are not GSM networks; if your handset is not capable of GSM (it must have a SIM card) then it will not possible for your calls to be intercepted by my equipment. That said, I invite all of my attendees to bring a GSM cellphone with them and participate – the more the merrier!