WEBVTT 00:00.700 --> 00:02.160 Welcome to my talk. 00:02.420 --> 00:05.580 I'm going to be chatting about wafer locks today and why they're awesome. 00:06.080 --> 00:14.100 It's going to be very theoretical, and it's going to be mainly coming at this from the lock engineer's perspective, if I might be allowed to flatter myself. 00:14.700 --> 00:17.880 I'll start by telling you a bit about who I am. 00:18.980 --> 00:22.280 And then I'll cover some definitions so that we're all on the same page. 00:22.520 --> 00:26.440 And then I'll show you a small selection of wafer locks through my eyes. 00:28.140 --> 00:32.260 So who is this loon who thinks wafer locks are pretty secure? 00:32.260 --> 00:53.340 Well, it all started about three years ago, when I thought it would be a good idea to design a challenge lock for HuxleyPig69, who is renowned in the lockpicking community for being the first person to publicly pick the Abloy Classic, and who designs tools for cracking high security locks non-destructively. 00:56.390 --> 01:04.570 In the last year or so of this now three-year journey, most of my focus has been taken up by wafer locks. 01:04.570 --> 01:20.390 And that's not because I've finally broken down mentally and started rambling, but rather because I genuinely think they offer a good solution to the problem of designing a high-security lock. 01:21.730 --> 01:24.270 So what makes a lock high security? 01:24.390 --> 01:28.810 Well, a lock is a reusable seal, which has two important properties. 01:28.810 --> 01:34.050 It's got to be tamper-evident, so that if the lock is defeated, it's obvious. 01:35.030 --> 01:42.010 And the second important feature is that defeating that lock should take as long as possible. 01:44.860 --> 01:55.030 Ideally, you're able to preclude covert and surreptitious attacks, and ideally an overt entry will take forever. 01:56.900 --> 02:04.910 An overt entry is one that is immediately obvious, so that's typically destructive attacks like drilling or using explosives. 02:06.740 --> 02:23.020 Covert entry is an attack on a lock that won't be immediately obvious to a casual observation, but if you were to strip the lock down and analyze it forensically, it will reveal what method was used to open it. 02:23.020 --> 02:29.120 So this normally covers lock picking and impressioning, because they leave small scratches and marks on the inside of the lock. 02:30.160 --> 02:39.900 And finally, there's surreptitious attacks, which don't leave any forensic trace whatsoever, and this would be stuff like duplicating the key from a photograph. 02:42.220 --> 02:52.980 And how high security a lock is is determined by the amount of time it takes to compromise a lock with an attack in each of those categories. 02:54.160 --> 02:56.400 Ideally, you wouldn't be measuring that in seconds. 02:56.400 --> 03:04.500 Ideally, you'd be measuring it in minutes or, you know, in a really, really good world where security engineers are doing a fantastic job in hours. 03:06.480 --> 03:25.280 So, since those locks are designed, or since high security locks are designed to make lock picking and impressioning attacks as difficult as possible, if not impossible, a lot of them have been designed with some very wacky mechanisms. 03:26.280 --> 03:36.540 So you can't always take the approach that you would normally take if you were picking a pin tumbler lock and apply that directly to a high security lock. 03:37.620 --> 03:43.360 So instead, I've kind of abstracted the lock picking process into these four requirements. 03:44.040 --> 03:51.280 You need to be able to get feedback from the lock, because that's how you tell what state the lock is in and how close you are to having it open. 03:51.420 --> 03:55.880 And it also tells you what your next step might be to get the lock open. 03:56.720 --> 04:01.680 You need to be able to manipulate and tension the lock simultaneously. 04:02.520 --> 04:15.680 So some locks like the Western Electric 30C or the Abloy Protech 2 have blocking mechanisms that, while not preventing manipulation or tension, prevent you from doing them both at the same time. 04:16.340 --> 04:20.100 And so they're phenomenally difficult locks to pick as a result. 04:20.960 --> 04:29.200 By tension, I mean applying a force on the lock in the direction that drives it to open. 04:30.280 --> 04:33.500 So how you do that depends on the particular kind of lock. 04:33.700 --> 04:53.040 But the key idea behind this is that since it's impossible to manufacture the components in a lock perfectly, and you have manufacturing tolerances, these manufacturing tolerances result in every single component being very slightly differently sized or shaped, 04:53.040 --> 04:58.860 which then causes them all to behave very slightly differently. 04:58.860 --> 05:07.400 And that's the case regardless of how well you machine the parts, and regardless of whether or not you have a very low quality lock or a very high quality lock. 05:08.720 --> 05:10.660 And finally, manipulation. 05:11.180 --> 05:18.040 Manipulation is just the ability to move the components inside the lock with a tool of some design. 05:20.160 --> 05:25.880 Those are the things to keep in mind when I start taking you through these locks. 05:27.200 --> 05:29.240 So what is a wafer lock? 05:29.500 --> 05:38.860 This should be pretty straightforward, but apparently for some people that that's not quite so clear. 05:39.440 --> 05:47.440 Some people whom I happen to have a lot of respect for, so that is not to criticize them in that sense, but I do disagree. 05:47.840 --> 05:56.440 And the reason I disagree sometimes with whether or not a lock is a wafer lock or not is because this is how I define it. 05:56.620 --> 06:02.360 And if you're working off a different definition, then obviously in some cases you're going to get to a different answer. 06:03.060 --> 06:07.700 So we've got some typical sliders shown in the top corner here. 06:08.280 --> 06:18.460 These two are from an Asidesmo, which is a reasonably high security lock, but not one that I would probably deem high security for the purposes of this talk. 06:19.080 --> 06:25.200 And these are from a cheap wafer lock, not wafer lock, slider lock. 06:27.320 --> 06:37.000 And in both cases they slide laterally and they have to be slid the correct distance to allow the lock to open. 06:38.380 --> 06:49.920 A wafer lock is a special kind of slider lock where the total length of the wafer is the same as the width of the core that they actually sit in. 06:50.000 --> 06:55.820 So here's an animation to kind of make that a little bit clearer. 06:56.900 --> 07:04.440 When the wafer is incorrectly positioned, it sticks out either one side or the other and prevents rotation. 07:04.440 --> 07:11.280 And when it's perfectly correctly positioned in the center there, it will allow rotation. 07:15.920 --> 07:27.820 So to start things off, let's take a look at the kind of wafer lock that you're probably familiar with and the kind of thing that probably sprang to mind when you first read the word wafer lock, if you've had any prior experience. 07:27.820 --> 07:33.880 If you haven't got any clue what a wafer lock is in a normal implementation, then that's exactly what I'm going to take you through. 07:35.160 --> 07:40.420 So at the top here we can see six wafers sticking out the top of this core. 07:42.440 --> 07:44.400 And this is the lock at rest. 07:46.460 --> 08:05.120 If we insert an incorrect key, or if we insert the correct key but not all the way, then what you'll see is that some wafers will stick out at the top and some wafers will stick out at the bottom of the core. 08:05.980 --> 08:07.740 And this will prevent rotation. 08:09.020 --> 08:23.620 When the key is fully inserted, or the correct key is fully inserted, then what happens is they all line up along the top and bottom edges of the plug, or the core, and they allow rotation of the core. 08:25.380 --> 08:26.940 So, excellent. 08:28.140 --> 08:30.420 But that's not a high security lock. 08:30.540 --> 08:36.840 There are three cuts per position and only six wafers, so that's not a very large number of differs. 08:37.680 --> 08:47.640 The core design makes it very easy to tension, you can just bend a piece of wire and insert that, apply rotational force, and voila, you have tension. 08:48.900 --> 08:58.380 And interestingly about wafer locks, you can't just design anti-pick shapes into them in the exact same way that you would a pin tumbler lock. 08:58.800 --> 09:07.520 It's possible to do, but it's a little bit more tricky than for a normal pin tumbler lock. 09:09.700 --> 09:25.060 So, now that I've shown you an example of a really bad wafer lock, let's revisit the actual principle behind wafer locks, and maybe I can show you a wafer lock that wouldn't be so easy to pick. 09:26.360 --> 09:32.320 The main idea here is to approach the design differently. 09:32.780 --> 09:54.740 So, rather than our cheap, low-quality wafer lock, which has a key which applies tension to the core, and then the core applies tension to the wafers, and ultimately opens the lock, we can achieve a much, much higher level of security if instead, we have the key only act on the wafers, 09:54.740 --> 09:56.720 and never directly act on the core. 09:57.240 --> 10:11.420 So, if we have a key that aligns the wafers correctly, and applies turning force to the wafers, and then the wafers transfer their turning force to the core, if they're correctly aligned, the lock will still work, but it's a lot, lot harder to tension. 10:13.080 --> 10:17.240 So, to show you what I'm talking about, here's another animation. 10:17.240 --> 10:19.980 This one, much less well-made than the other one. 10:21.800 --> 10:34.540 This grey bit in the middle is our key, the beige-yellow element is the wafer, the part highlighted in blue is the core, and all around the outside in grey again is the housing. 10:36.280 --> 10:48.040 So, the way this works, the key is longer on one side than it is on the other, and when we turn it clockwise, it makes contact with the wafer on one side first. 10:48.040 --> 10:53.680 So, in this case, it makes contact at the bottom, and that causes the wafer to slide to the left. 10:54.960 --> 11:09.960 And the wafer slides to the left until it meets the other side of the key, at which point there's no longer a lateral motion for the wafer, but instead it gets jammed in place like that, and the force on it becomes a rotational force. 11:10.560 --> 11:19.680 In this case, the wafer is correctly aligned, so that rotational force is then transferred to the core, and that results in the core turning. 11:20.440 --> 11:29.200 If it weren't correctly aligned, then what would happen instead is that rotational force would be applied to the housing, and the core wouldn't move at all. 11:32.100 --> 11:40.660 If you want to have a system that works that way, then there are two key requirements that you need to meet. 11:41.100 --> 11:48.320 Firstly, as I just mentioned, the wafer has to be aligned correctly, otherwise it's going to apply that rotational force to the housing, and nothing will move. 11:49.440 --> 11:55.400 And secondly, the key must have at least two points of contact on the wafer, on opposing sides of the wafer. 11:55.400 --> 12:01.480 That's the point at which that lateral force is translated into a rotational force. 12:05.320 --> 12:11.320 That's something to keep in mind for later when we take a look at some of the more interesting locks. 12:12.900 --> 12:26.520 So the main implication of this is that the lock becomes ludicrously difficult to tension, because traditionally what you would do is you'd apply tension as the first step in the lock process. 12:28.020 --> 12:32.040 And when you do that, at least one of the elements is going to bind in some way. 12:32.220 --> 12:41.940 And then you can reach through with some kind of tool and prod on those elements until you find one that's binding, and that's the one that you know you need to move. 12:41.940 --> 12:45.880 And you can move until it stops binding, at which point you know you've correctly positioned it. 12:46.540 --> 12:54.540 But that's not possible with this, because in this case you're going to have to align one of the wafers correctly first in order to apply tension. 12:55.000 --> 13:01.780 And since you can't apply tension before that point in order to know where to place it, you have to guess. 13:02.580 --> 13:11.300 So in the example animation that we just looked at, if I go back, there are six possible positions. 13:11.460 --> 13:17.940 So that means you would need a tool that has six different ends on it to simulate the key at that point. 13:19.100 --> 13:37.040 And what that means is that because only one of those tools will work, the whole lock picking process, and how quickly you can open that lock covertly, is massively extended, because you're going to have to test each of those tools until you find one that works. 13:37.040 --> 13:40.420 And on average, it would take you three and a half tries. 13:40.500 --> 13:56.180 So the amount of time it would take is massively increased, because that's the requirement before you can even begin the lock picking process, compared to other kinds of lock, where you can just apply tension and get started straight away. 14:01.520 --> 14:06.600 So the main wafer lock that I want to look at is the Chroma Protector. 14:09.240 --> 14:13.920 But there are a number of problems looking at the Chroma Protector. 14:14.720 --> 14:22.680 At the time that I started thinking about it, I didn't own one, so that made looking at how it worked tricky. 14:24.860 --> 14:27.920 And generally, information on it is scarce. 14:27.980 --> 14:31.460 Here are the sources that I've found and I've learned from. 14:31.960 --> 14:41.200 It's worth noting that Graham Pulford, in his book High Security Mechanical Locks, refers to the Chroma Protector as a lever lock. 14:41.900 --> 14:47.080 Now he does this because he categorizes locks based off the design of the keys. 14:48.160 --> 14:54.240 But I think it would be very misleading to describe the Chroma Protector as anything other than a wafer lock. 14:55.860 --> 15:09.480 And if you really want to dig into the detail of the Chroma Protector and exactly how it works, Jakob Fagerlund's talk is absolutely fantastic and I highly, highly recommend it. 15:12.420 --> 15:31.340 So as I was saying, the Chroma Protector is a lock that I didn't have access to, so there was a motivation to make one for myself and so that I could test whether or not it worked in the way that I thought it did. 15:31.340 --> 15:37.720 I'd been thinking about it theoretically for quite a long time, but things don't always translate into practice in the same way. 15:37.720 --> 15:46.320 So I wanted a prototype that I could play around with and that would prove whether or not it worked in the way I expected it to. 15:48.000 --> 16:02.120 The other reason is, when you design a lock, you tend to gain a lot of insight into how that mechanism works and why some of the design features have developed in the way that they have. 16:02.160 --> 16:16.520 And so my hope was that since the Chroma Protector is a reasonably complicated lock in terms of some of the particular security features that are found in it, that I might gain some extra insight. 16:20.520 --> 16:33.880 So I've previously designed locks and the only one that I ever produced was made of three millimeter plywood sections cut with a laser cutter. 16:34.060 --> 16:46.580 So that's exactly what I wanted to do again with the Chroma Protector because I had access to a laser cutter and I had access to 3D printers and so that was the logical step for me. 16:46.620 --> 16:49.460 And I couldn't see any reason why the design couldn't work that way. 16:49.680 --> 17:12.430 I wanted to fit the same size as the Chroma Protector that I now have because if you design with the same constraints as the actual engineers who designed the lock, whose inspiration you're taking, you'll get a better understanding of why they've made those decisions. 17:12.430 --> 17:16.310 If I didn't limit myself in that way, I might miss important details. 17:18.030 --> 17:25.630 And finally, I wanted to include all of the different basic possible way for designs that I had found in patents up until that time. 17:26.150 --> 17:36.010 So if I take you back here, there are some examples, but we'll dig into that in just a little bit. 17:36.250 --> 17:41.130 Some of the other requirements that I set for myself were that I wanted it to be springless. 17:42.090 --> 18:04.990 And I wanted it to be springless because A, I couldn't see a good reason why the mechanism needed springs at the time, and B, because most safe locks are designed so that since springs fail generally first, most safe locks are designed so that they are not dependent on those springs in order to function. 18:06.650 --> 18:12.710 Because you don't want to have your secure lock inside your secure container fail on you. 18:14.190 --> 18:27.730 And also adding them, point B, is a bit of a pain and makes designing them a lot harder, designing the whole lock a little bit harder, especially if I were then to give this design to other people for them to learn about. 18:30.430 --> 18:38.970 I wanted it to be as high security as you can possibly get, considering I'm making it out of three millimeter plywood. 18:40.630 --> 18:57.610 So I didn't, in terms of non-destructive entry, I didn't want it to be possible to just look at the insides of the wafers through the keyway and from their shapes discern what the bitting on the key needed to be, or needs to be to get that lock open. 18:58.010 --> 19:06.670 I also didn't want it to be possible to just push the wafers to their maximum range, left and right, and for that to be different. 19:07.930 --> 19:22.170 Because if that's different and has any kind of relationship to the actual length on the sides of the wafers, then you can rapidly gain an idea of what the key has to look like. 19:24.530 --> 19:27.570 And then I wanted the lock to also be self-scrambling. 19:28.450 --> 19:38.590 So self-scrambling is this concept that all locks do, and lots of locks do this through having springs, but that's not necessarily required. 19:38.590 --> 19:49.990 The idea behind a self-scrambling lock is simply that when you insert the key to open the lock, and you turn that key, it aligns all the components in their correct positions. 19:50.630 --> 20:05.050 And if you then close the lock, one of the important things would be to scramble the positions of those components so that the next person coming along who looks at the lock after you've locked it doesn't just need to stick in a small bit of wire and apply a bit of tension, 20:05.050 --> 20:06.370 and the lock pops open. 20:08.390 --> 20:11.670 I didn't want it to be a central wafer position. 20:11.710 --> 20:15.690 This was kind of just a minor I-want-to-be-annoying feature. 20:16.410 --> 20:34.070 If a wafer were correctly positioned dead center, it would be substantially easier to tension than any of the other designs, because any tool that has equally length bits on either side would be sufficient to tension. 20:34.810 --> 20:37.310 Whereas that's not the case for any of the other positions. 20:37.330 --> 20:42.690 So I thought if I could take that out of the equation, that would make the lock just a little bit more secure. 20:44.270 --> 20:47.130 And the final problem that I ran into was reliability. 20:47.130 --> 21:02.810 So this is kind of related to the spring, what I was saying about springs earlier, but this is kind of just the idea that there shouldn't be a possible position that the wafers could get themselves into where you couldn't insert the key into the lock. 21:04.230 --> 21:07.150 Unfortunately, that's something I failed on. 21:07.670 --> 21:22.790 I couldn't balance making my lock without any springs, having it be self-scrambling, and have there been no possible positions which the wafers could get into where the key couldn't be inserted into the lock. 21:23.190 --> 21:29.970 That was just beyond my ability as a self-taught engineer to resolve. 21:31.370 --> 21:33.690 So, what I came up with. 21:34.410 --> 21:36.590 I used a 3D printed key. 21:37.130 --> 21:39.890 The lock itself contains seven wafers. 21:40.550 --> 21:47.430 The key is tip-stopped, and the key has a very mild profile, so you can't insert it the wrong way. 21:47.490 --> 21:58.070 And it will align both at the end and at the neck, basically, or at the collar of the key. 21:58.070 --> 21:59.790 So that helps with alignment. 21:59.970 --> 22:04.490 And it breaks itself open. 22:05.930 --> 22:12.370 So this was the most important thing that I learned when designing this, when I finally had it in my hands. 22:13.230 --> 22:21.190 You need two points of contact on a wafer in order to rotate it, or in order to tension with it. 22:21.190 --> 22:37.150 And that's all well and good in the opening direction, but I found as soon as I reversed the key, there was no more than one point of contact on any of the wafers, and so the key can't turn the core backwards. 22:37.610 --> 22:40.810 And so once you open it, it stays open. 22:42.910 --> 22:45.270 Which is a little bit unfortunate. 22:47.130 --> 22:55.330 But nevertheless, I'll do my best to make the files available for others to play with. 22:56.350 --> 23:04.430 Here are the four basic wafer shapes that I ended up creating, and they all work, in the open direction at least. 23:04.430 --> 23:07.490 On the bottom right, we have a full wafer. 23:08.150 --> 23:14.190 This is the bog standard wafer, and most closely resembles what you'd see in other kinds of wafer lock. 23:14.830 --> 23:17.250 On the bottom left, we have a half wafer. 23:17.410 --> 23:33.530 The idea being that it's missing one half of the surface, so the key can't tension off this wafer in order to drive the core around, but it still needs to align that wafer correctly in order for the lock to open. 23:33.650 --> 23:40.570 So that makes it a little bit harder to attack, because this wafer would be much harder to tension than a full wafer. 23:41.570 --> 23:48.650 Up here on the top right, we have a split wafer that doesn't have a limit on it at either end. 23:48.890 --> 23:52.670 So this basically functions like two half wafers. 23:52.670 --> 23:59.430 So you need to align both of them correctly, and they're actually different cuts for each of them. 24:01.470 --> 24:24.770 And then lastly, in the top left, we have the limited split wafer, which requires that the key be the correct length in order to drive both these halves together, so that their total length is the same as the core is wide. 24:24.950 --> 24:29.130 But they also need to be aligned correctly left to right. 24:29.830 --> 24:36.910 And the hope was that that would be particularly difficult to manipulate, and I want to see how that bound up when it did. 24:40.750 --> 24:43.170 So my analysis of it. 24:43.990 --> 24:49.490 You can't easily decode it, and it does work in the opening direction. 24:49.490 --> 24:51.070 It does self-scramble, 24:56.210 --> 25:02.110 and it might be non-trivial to destroy if it weren't made of three millimeter plywood sections. 25:03.330 --> 25:12.470 But all in all, probably not something you're going to want to use in a safe, especially not when you could use something like this. 25:13.630 --> 25:22.170 So this is really the inspiration for my design, and I'm not going to claim any great originality with what I created. 25:22.170 --> 25:26.510 I was hoping to just create a simplified version of this. 25:27.410 --> 25:29.890 So I'll give you some basic details about it. 25:29.890 --> 25:34.050 It's 68 millimeters across, and it weighs 730 grams. 25:34.050 --> 25:36.350 It is not a small lock. 25:36.630 --> 25:45.230 It contains 11 wafers, which from a brief reading of the key, have at least seven possible cuts per position. 25:46.370 --> 25:48.310 There may be more. 25:49.050 --> 26:14.950 In practice, there are probably fewer in lots of positions, because although in theory any of the layers are completely interchangeable, in practice, at least for the ones that I have seen and that Jaco analyzed in his talk, there seem to be certain patterns of wafers where some of them don't actually vary very often in position or cut. 26:16.990 --> 26:20.910 So two things to note about my Chroma lock. 26:20.910 --> 26:22.850 One, it's not made by Chroma. 26:23.150 --> 26:31.990 I suspect heavily that it is made by Carl Wittkop or Carvey, which is a German safe manufacturer, presumably under license. 26:32.230 --> 26:39.610 And the second detail is that I'm pretty sure that my Chroma Protector is not the latest version of Chroma Protector. 26:40.550 --> 26:52.230 However, this was the same Chroma Protector as Jaco was covering in his talk, and so I feel pretty happy that there's still some benefit worth looking at this. 26:54.270 --> 26:58.250 So we'll start by looking at the key, because the key is pretty complicated. 26:59.610 --> 27:02.850 And there are a whole bunch of details to pick out. 27:03.310 --> 27:06.390 Here are the seven that I've decided to pick out. 27:06.390 --> 27:09.910 So the Chroma Protector has a post. 27:10.170 --> 27:22.790 So it's basically got a large spike that runs the length of the lock down the center, which helps align the key, but also removes space that you'd want if you were going to design a tool to fit into the keyway and to manipulate the wafers. 27:25.230 --> 27:27.070 It's also got this ramp. 27:28.150 --> 27:46.330 And if you design a tool to fit inside the lock that doesn't have this ramp, what you'll find is that one of the wafers has a portion of it that sticks into the keyway, and so you won't be able to insert your tool all the way into the lock unless you simulate this ramp. 27:47.650 --> 28:03.870 And interestingly, at least in principle, if you were designing a tool, you'd need to have that ramp on both sides so that you can push the tool in and pull it back out, back past that little ledge on that wafer when that wafer springs back into position. 28:05.710 --> 28:14.630 But the problem you're going to run into is that this ramp is the same width as one cut. 28:15.090 --> 28:19.650 So if you're designing a tool, what you really want is you want a tool that allows you to manipulate wafers individually. 28:19.650 --> 28:24.350 You don't want to have a tool that's so thick that it's going to manipulate two wafers at a time. 28:24.350 --> 28:28.970 That would make it phenomenally difficult to position each one of them individually correctly. 28:31.050 --> 28:39.390 So you'd be in a bit of a bind in terms of how to handle this ramp. 28:39.490 --> 28:47.690 The last option would be to create a half-height ramp and make your tool a little bit smaller than the total space that you've got. 28:49.130 --> 28:51.670 But again, that's not really ideal. 28:53.910 --> 29:09.650 Then we've got these angled cuts which, to the best of my knowledge, are just there to make key duplication harder because, as I mentioned way back near the beginning of the talk, key duplication is one of the possible methods of surreptitious entry. 29:09.810 --> 29:14.330 So for a high security lock, you want to make key duplication as difficult as possible. 29:14.890 --> 29:18.370 So those angled cuts look like they're about 45 degrees. 29:18.370 --> 29:23.950 I haven't measured, but they look like they're about 45 degrees and they make key duplication much harder. 29:24.490 --> 29:26.850 There's also this weird angled cut. 29:26.850 --> 29:35.750 If you look closely, you can see that each of these other cuts on the key are horizontal except this one. 29:35.750 --> 29:48.850 And this one actually cuts across more than one wafer and engages a flexible portion on the corresponding wafer, which I believe is wafer 9 in this particular case. 29:49.450 --> 30:03.790 Again, I believe this is for key duplication because, from what Jaakko said about chroma protectors that he's looked at, it's not been necessary to have that cut on a tool. 30:04.550 --> 30:07.030 And that's also definitely the case for my lock. 30:07.890 --> 30:13.510 But still, it's another interesting feature that would make duplicating this key very, very tricky. 30:14.010 --> 30:22.570 I've got these partial radial cuts which cut into the bitting of the key, but not all the way through. 30:23.350 --> 30:35.690 And again, there's a potential there to make key duplication much harder if they truly need to be cut out in order to allow correct alignment of the wafer. 30:36.250 --> 30:48.150 You could probably, in most cases, get away with this and not worry about it if you were designing a tool to manipulate the wafers, but this is yet another thing to worry about if you were going to try and copy one of these keys. 30:50.830 --> 31:02.070 Then we've got what is probably the most interesting feature, I would say, on the lock, or sorry, on the key for me, which is this undercut. 31:02.810 --> 31:10.490 And this undercut is a cut that's made so deeply that it cuts into the actual shank of the key. 31:11.690 --> 31:23.890 And so when you insert the key, the particular portion of the wafer that engages with this undercut first has to meet this ramp, and so you need this sort of slot on the key. 31:25.350 --> 31:38.090 And if it's able to, it'll travel all the way up, and it'll stop when the key is fully seated in line with the undercut, and then as you turn the key, the undercut will pass through the interposition. 31:38.910 --> 31:54.450 Now, that doesn't actually mean that you couldn't design a tool that uses the whole shank space, but you could design the undercut to cut so deeply that it even cuts all the way through to the post. 31:55.530 --> 32:05.590 And if you did that, the key would have a hole in it, which wouldn't be a big deal for the key because it's solid, and that would only be one tiny weak point that would be relatively well supported. 32:05.970 --> 32:18.950 But if you're going to design a tool and that undercut could be in any position, well, that's a tricky problem to design around, and it would multiply the number of tools that you would reasonably need in order to open this lock. 32:18.950 --> 32:25.090 Now remember, you'd need to line one of those wafers up correctly in order to tension the lock anyway. 32:25.670 --> 32:44.130 So you'd need seven different tips on your tool, and you might need several different shafts, and it might not be possible to create those separately and viably, so assuming you had seven different ends and 11 wafers where that undercut could exist, well, 32:44.130 --> 32:49.670 that's 77 different tools that you'd need to bring on a job of which only one of them will work. 32:49.670 --> 33:05.710 So this is a huge exaggeration of the problem, which would hugely increase the amount of time it would take in order to reliably manipulate open one of these locks, even if you did have a tool that could do it. 33:08.330 --> 33:10.530 And finally, we have this dimpled cut. 33:10.530 --> 33:19.790 Now, Jaakko didn't actually have an answer... Jaakko didn't actually have an answer to this in his talk as to what it's there for. 33:20.330 --> 33:23.690 And I should point out, I am not an expert on this lock. 33:23.730 --> 33:28.010 That title almost certainly belongs to some German safe mechanic. 33:28.290 --> 33:31.750 But I can offer a theory. 33:32.490 --> 33:40.470 And that theory is that the fourth wafer in the Chromium Protector handles counter-rotation. 33:40.810 --> 33:50.770 So the Chromium Protector handles counter-rotation by allowing essentially the full movement of the key to about 45 degrees within the lock. 33:50.790 --> 33:58.970 And so at any point that you are opening the lock, you can turn the key back basically the whole way, or back basically 45 degrees. 34:00.730 --> 34:12.650 If you do that, then what you'll find is that the fourth wafer in this particular case, it's cut so that it makes contact with both sides of the key simultaneously. 34:12.650 --> 34:21.070 And that wafer handles the counter-rotation of the core, which is the missing element in the lock that I created. 34:22.910 --> 34:41.930 However, if you don't have this dimpled cut on this surface of the key, then what happens when you attempt to turn the lock, to turn the key backwards in the lock, is that you actually make contact with a protrusion on wafer number nine before the key makes contact on two points with wafer number four. 34:42.550 --> 35:00.450 And so exactly the same, at least in theory, as with my lock, you'd be trapped in a position where you only have one point of contact with any wafer in the lock, and so you can't easily counter-rotate the lock, because the harder you turn backwards, the harder you force the wafer against the side of the housing, 35:00.450 --> 35:03.110 and the greater the frictional forces. 35:04.610 --> 35:21.670 So my theory is that this is another trap when it comes to key duplication, where if you failed to replicate that sufficiently well, what would happen is that even though you may have a key that opens the lock, you then wouldn't be able to remove the key from the lock, 35:21.670 --> 35:35.010 and so the key would remain inside the lock, and the lock would still be tamper-evident, even though it had been successfully defeated, which was one of the requirements for a high security lock. 35:39.930 --> 35:44.670 To move away from the key and back to the lock, let's take a look at the keyway. 35:44.670 --> 35:47.570 There is no core that you can tension up. 35:47.570 --> 35:51.710 This is a solid plate that's held in with three screws. 35:55.800 --> 36:12.060 There is no way to tension the lock directly around the keyway, and in the center you can see the poster, which matches the hole in the key, and you can start to see some of the different shapes of the wafers through the keyway. 36:13.420 --> 36:29.520 Here it is with that top layer taken off, and so we can see the top layer, layer 11, which is one of those split wafers, and it's the only wafer, or set of wafers in this lock, the only layer that isn't actually sprung. 36:32.240 --> 36:46.200 And we can kind of see looking down that we have, here's the little portion that sticks out that engages with the ramp, and this little slightly curved portion is the portion that engages with the weird angled cut. 36:46.880 --> 36:52.000 And you can sort of see that every single wafer all the way down is very differently shaped. 36:52.600 --> 37:08.500 And so as a result, it's very, very difficult to look at them and try and discern any kind of meaningful pattern in order to decode which position that wafer might need to be placed in order to open the lock. 37:11.490 --> 37:20.910 Having now covered the basic idea behind the wafers, and without digging too much into how each of them works, there are two wafers that I'm going to draw particular focus to. 37:22.810 --> 37:29.490 The first wafer is number 7 in my lock, which has a square cut out in one corner of the wafer end. 37:29.950 --> 37:37.790 This effectively acts a bit like a false gate does on a traditional on traditional slide locks, albeit less effectively. 37:37.910 --> 37:45.050 And this is one of the reasons why I think false gates spooling and serrations aren't so simple when it comes to wafer locks. 37:46.470 --> 37:56.190 For this cut out to have an effect, all the other wafers would first have to be set correctly, and then the core will turn partially and stop getting caught in this cut out. 37:56.710 --> 37:59.850 Sounds like it'd hamper an attacker pretty effectively, right? 38:00.690 --> 38:04.530 Except there's no way for the other wafers to counter-rotate the core. 38:05.110 --> 38:11.330 The wafer itself supplies no counter-rotation either, because it can't with the notch squared off. 38:12.150 --> 38:17.890 And what this means is that an attacker needs only to keep pushing on the wafers until they finally fall into place. 38:18.010 --> 38:22.950 They can't lose progress towards getting the lock open, they can only really gain progress. 38:24.210 --> 38:27.570 So that was the boring detail of the two. 38:27.570 --> 38:35.630 The other one reveals what I think personally is the Achilles heel of all wafer locks design's tension of the wafers. 38:36.190 --> 38:44.930 And yes, I think they're high security, but I still think they do have a fundamental problem, and it's a very difficult one to grapple with. 38:46.010 --> 38:56.190 And I think that problem is essentially getting the lock to counter-rotate open again when you're using those wafers to tension the lock to open it. 38:56.770 --> 38:58.630 I mean, of course I think that, right? 38:58.630 --> 39:04.310 Because that's the design feature that I overlooked in my own design, right? 39:05.930 --> 39:09.810 But I then did a lot of thinking about how to solve that problem. 39:10.870 --> 39:17.090 So the animation on the left here is the most obvious and basic approach to solving that problem. 39:17.330 --> 39:31.250 You've kind of got this like bow tie or hourglass style cutout, and essentially any bit on the key when turned, in this case 45 degrees, will begin to tension the lock. 39:32.310 --> 39:46.150 And as long as nothing blocks the key when it's counter-rotating, you can counter-rotate or make contact on two surfaces again, and it'll counter-rotate really smoothly. 39:46.150 --> 39:54.510 The only problem with this is this wafer doesn't have the freedom to move at all, and so it'll trivially... 39:55.810 --> 40:05.130 it'll allow the lock to be tensioned trivially, which undoes the whole point in designing the lock to tension off the wafers in the first place. 40:05.990 --> 40:12.290 So the way they've tried to do this in the chroma is a little bit more complicated than that. 40:12.490 --> 40:21.950 If you take a look at the animation on the right hand side, this is the exact same animation as the one on the left, just with a little bit more material cut away. 40:22.790 --> 40:34.910 It still functions in exactly the same way, but hopefully you can see the similarities between the animation on the right hand side and wafer number four in my chroma lock. 40:37.460 --> 40:51.200 The only difference between the animation on the right and the actual wafer in my lock is that in the top right hand corner they haven't given the same surface to tension off as in the animation. 40:51.900 --> 40:58.920 They've got a surface which the key needs to touch and move laterally into the position. 41:02.200 --> 41:19.140 But when you design the wafer this way, what you'll find is that the the prong that sticks out here on the bottom right hand side obstructs the keyway. 41:19.880 --> 41:27.220 And in fact you might even be able to see this kind of darker portion on it where that surface has kind of been rubbed away a little bit or has become worn. 41:27.260 --> 41:34.380 And the reason for that is this is the portion of the wafer that makes contact with the ramp on the key. 41:36.520 --> 41:50.610 And so the real reason to have the ramp is to correctly, well to allow the key to enter the lock while not having to have this counter rotation wafer already set in the correct position. 41:53.030 --> 42:02.050 Attacking wise though, these two surfaces on the key need to engage at the same time. 42:03.150 --> 42:13.470 So if you have any tool which is equally lengthed and you counter rotate in the wrong direction deliberately, you will align this wafer correctly. 42:14.270 --> 42:32.730 And if you had some kind of method of then identifying how far away the surface is that the key would have to make contact with in order to tension it clockwise, then you'd know the correct position of at least one wafer and you could decode that. 42:34.910 --> 42:37.230 And that would allow you to tension the lock. 42:40.950 --> 42:49.830 So ultimately is this lock impossible to breach or manipulate or pick? 42:49.930 --> 42:59.050 No, there have been reports of people managing it, at least against some versions of the lock, even if there aren't any recordings on YouTube. 43:00.230 --> 43:03.490 But this is also a phenomenally high security lock. 43:03.610 --> 43:18.650 It is hugely drill resistant, it uses a special plate right at the bottom of the keyway to add extra drill resistance on top of the already significant resistance of the plates that sit on top of the lock and effectively function as the faceplate. 43:20.850 --> 43:34.370 The kind of totally patternless way that most of the inside surfaces of all the wafers have been cut away means that it's incredibly difficult to decode. 43:34.730 --> 43:45.390 And in a best case scenario, if you had huge number of samples, thousands of these locks, then you'd be able to maybe carry out some kind of decoding. 43:45.690 --> 43:59.710 In a worst case scenario, for the attacker at least, what will be happening at the factory is they will truly do something to randomize all of those shapes and so there will never be a pattern no matter how many samples you collect. 44:01.250 --> 44:17.330 There's no way for us to easily work out which one is the case, but it does seem like it would take a phenomenal amount of resources to work out how to decode one of these locks. 44:20.850 --> 44:25.750 I didn't really discuss the blow ring at all, but that's something to discuss. 44:25.750 --> 44:32.130 So around the back of the lock is a... if we can go 44:36.090 --> 44:36.490 back... 44:36.490 --> 44:43.460 oh boy, okay, that's a bit further than I want to go back. 44:43.460 --> 44:44.580 Right, so there we go. 44:45.440 --> 44:50.520 The brass ring that sits around the outer edge of this lock is the blow ring. 44:51.300 --> 45:04.960 And from my understanding, the way that it's designed is so that if you pack the middle of the lock through the keyway with explosive, which is one of the big downsides of keyed safe locks, is that you can pack them full of explosive. 45:06.960 --> 45:25.140 When you detonate that explosive to create high pressure to tear the lock apart, rather than the entire lock completely tearing itself to pieces, what happens instead is the blow ring gives way under the high pressure before the lock actually does dismantle itself, 45:25.140 --> 45:31.360 since the blow ring is much softer metal than the rest of the body. 45:33.140 --> 45:44.300 And so what will happen is you'll end up fusing together all the various wafers in the middle into one horrible blob, and the lock won't be opened. 45:45.480 --> 45:49.880 And so at that point the only option would be to completely obliterate the lock. 45:50.540 --> 46:07.060 And considering this is normally used in high security containers or vaults, this sort of thing, that means you have to go through the entire surface of that vault or container, which will be no easy feat. 46:10.250 --> 46:17.790 And that brings me on to the the final point, which is the super super tight tolerances. 46:17.870 --> 46:28.490 So I've attempted to manipulate my lock with the face cover removed and applying direct tension to the core, which obviously is cheating, right? 46:28.490 --> 46:33.330 You wouldn't be able to do that if the lock were actually installed in a container. 46:33.530 --> 47:00.230 But even doing that, even basically ignoring the main security feature that the lock has, and attempting to manipulate it like that, the tolerances are so incredibly tight that with even more than two or three wafers, I can't manipulate the lock and have the wafers hold in place even when they bind. 47:00.410 --> 47:14.590 They do bind, and it's possible to detect that with enough force, and it's possible to move them into position, but they drop really really easily, which makes it phenomenally hard to manipulate. 47:15.470 --> 47:20.410 And all in all, I would say this is a phenomenally secure lock. 47:21.690 --> 47:27.150 And it largely achieves the goals that high security locks have. 47:28.390 --> 47:30.430 And it's a wafer lock. 47:30.430 --> 47:45.370 So clearly, there is some potential for wafer locks to provide security that we're looking for in high security locks in a way that isn't perhaps as inherent to, for example, pin tumble locks. 47:45.370 --> 47:52.490 I can't think of a pin tumble lock that has a comparable challenge with tensioning or manipulation. 47:55.550 --> 47:57.390 So there we go. 47:58.910 --> 48:25.430 Hopefully I've convinced you that while lots of wafer locks are low security, the wafer lock principle itself, especially when you have the key tension, the wafers, which then tensions the core, is actually really really quite high security, and it's got great potential to deliver a much higher security solution than other types of lock design. 48:28.810 --> 48:31.170 So hopefully you learned something. 48:31.350 --> 48:33.090 Hopefully I convinced you. 48:33.310 --> 48:38.130 And I presume now we will lead into the question and answer section. 48:38.130 --> 48:39.870 Thank you very much.