Re: Bank transactions on Internet
At 12:13 AM 4/9/96 -0700, Steve Reid wrote:
Is it really that easy to break 40-bit? Don't you need access to a "fair amount of cpu power" to brute force crack 40bit?
I remember reading a recent paper at this URL: http://theory.lcs.mit.edu/~rivest/bsa-final-report.ascii They mentioned a Field Programmable Gate Array (FPGA), specifically a board-mounted AT&T Orca chip available for around $400. They said it could crack a 40-bit key in 5 hours (average). Sounds like anyone with root access on a major internet node could make a significant profit stealing credit card numbers.
The FPGA sounds like a very interesting device, with quite a few legitimate uses... Has anyone out there seen one of these?
I was hoping a hardware type would answer this question, and give references to manufacture's spec sheets, but not having seen such an answer, here is a software person's answer. Gate arrays are a common part of complex electronics. If you are viewing this answer on a screen, it is quite probable that there is one right before your nose. They come in two basic forms, mask programmed and field programmed. Mask programmed gate arrays are an array of logic gates, which are "programmed" to an application by a final metalization layer. They are quite inexpensive when ordered in quantity. Field Programmed Gate Arrays (FPGAs) are designed for prototyping designs, and can programmed electrically. ------------------------------------------------------------------------ Bill Frantz | The CDA means | Periwinkle -- Computer Consulting (408)356-8506 | lost jobs and | 16345 Englewood Ave. frantz@netcom.com | dead teenagers | Los Gatos, CA 95032, USA
At 12:13 AM 4/9/96 -0700, Steve Reid wrote:
Is it really that easy to break 40-bit? Don't you need access to a "fair amount of cpu power" to brute force crack 40bit?
I remember reading a recent paper at this URL: http://theory.lcs.mit.edu/~rivest/bsa-final-report.ascii They mentioned a Field Programmable Gate Array (FPGA), specifically a board-mounted AT&T Orca chip available for around $400. They said it could crack a 40-bit key in 5 hours (average). Sounds like anyone with root access on a major internet node could make a significant profit stealing credit card numbers.
The FPGA sounds like a very interesting device, with quite a few legitimate uses... Has anyone out there seen one of these?
I was hoping a hardware type would answer this question, and give references to manufacture's spec sheets, but not having seen such an answer, here is a software person's answer.
As a hardware(and sometimes software) type who has used these sorts of parts in real designs several things need be said. First, the $400 cost is about what the physical chip and test board would cost, it does not include the cost of the software packages required to generate the programming information for the chip and simulate and verify the design. While this software can sometimes be pirated or "borrowed" from an employer or school or even the chip distributors, charges for a legitimate copy of the software for programming many kinds of FPGA's can run in the low to mid thousands and it it is usually dongle protected. And the more advanced software packages that take high level descriptions of the logic in languages such as VHDL and compile them into the special optimized forms required to get speed out of FPGAs with highly assymetric routing delays through their interconnect networks are considerably more expensive and may require RISC workstation hardware (most of them ran only on Suns or HP in the past) and unix rather than just a high end PC running Win 95. Costs of this sort of software package and workstation run as high as $50K per seat. And it is rather unlikely that one could make a high clock speed high performance hardware based key cracker work without traditional high speed logic debugging tools such as a fast logic analyzer (if we are talking 5-10 ns clock especially) and a 1 ghz or so digital scope. These kinds of gear, though sometimes available after hours to engineers working for more liberal companies or schools, cost many thousands of dollars and are not garden variety items available to any hacker. And finally, depending on the technology of the part being used, there may be a significant cost in the order of at least hundreds if not thousands of dollars for a specialized programmer capable of programming ("burning") the FPGA with the interconnect patterns generated by the software. These tend to either be specialized to one kind of part and maybe modestly cheap (hundreds of dollars) or universal and several thousands of dollars (such as DataIO gear). And at least in my experiance (I may be unusually stupid and careless and clumsy or may not be) even if the parts are a few times reprogrammable (as CMOS FPGAs often are these days) one can assume that one will fry, or break the pins off, or reprogram one time too many the FPGA or FPGA's before one gets the design working. This means that it would be realistic to assume several parts would be consumed by the prototyping effort, they may not be cheap and this adds up too. So whilst someone working with these parts as part of their job or schooling might well have access to all the required resources on an informal basis and be able to build a key cracker in evenings or weekends for little more than the cost of the chip and a PC board to hold it, it should be realistically noted that the actual cost of equiping a lab from scratch with the required resources is more on the order of tens to hundreds of thousands of dollars rather than $400. I must hasten to add that high density FPGAs have many many legitimate uses in prototyping logic and producing products in small volumes too small to justify the tooling costs of doing mask programmed gate arrays (which tend to be significantly faster and easier to design, but cost $5-100K NRE to set up custom masks for fabrication). The current generation of them make it possible to build logic systems in one small chip that a few years ago would have been large PC boards full of PALs and other logic. Actually designing a workable key cracker for say RC-4 would be a significant design challenge even with current parts, but probably not something that someone skilled in the art (and of course reasonably bright) couldn't handle. (At first blush I think in the case of RC-4 the pipelined key scheduling logic required would be the very hard thing to make efficient). And the availablity of simulation and timing analysis tools would make the process of creating such a deamon largely a software or logic programming exercise that could be mostly carried out over weeks or months of effort on a workstation or high performance PC, rather than something that requires the intensive resources of an extensive hardware lab for a long period. Unfortunately, like so many hacker projects these days, the cost of reproducing multiple copies of a cracker and the skill level required is very minimal compared to the real logic programming talent and architectural insight it would take to fit one into a FPGA or two. So once one is built, there can be hundreds or thousands of copies made and put to work in the underground by all sorts of evil people who wouldn't have a prayer of designing one from scratch, Dave Emery die@die.com
At 12:13 AM 4/9/96 -0700, Steve Reid wrote: a board-mounted AT&T Orca chip available for around $400. They said it could crack a 40-bit key in 5 hours (average)... ... Has anyone out there seen one of these?
"Dave Emery" <die@pig.die.com> pessimised:
[... the tools are too expensive...] [... and the skills required are too high...] [... for anyone on cypherpunks...]
Come on, Dave, this isn't alt.2600! Most of the subscribers to this list are professionals -- engineers, programmers, mathematicians, lawyers -- not phone phreaks. I'm sure that there are more than a few of us with the knowledge, experience, and free access to the resources needed to handle most relatively small-scale designs like this. (It's like saying that no one on cypherpunks has access to the distributed computing resources necessary to perform other sorts of brute-force cracking -- which is patently ludicrous.) For instance, from where I'm sitting in my *home* office, I can see the full development packages for Xilinx and AT&T FPGAs, Viewlogic VHDL, schematic, and simulation tools, an HP 1660A logic analyser, and a Tek THS 720 500 MHz digital scope. And I doubt if I'm the only one here who does this for a living. The problem isn't resources, but time and motivation -- what sort of situation would it take to get me (for instance), and one of cypherpunk's cryptography wizards, to take the time to collaborate on something like this. (BTW, if you're willing to break the design into a couple of FPGAs, like the Motorola MPA 1000 devices, you can find all the software you need for free...) -- Roger Williams PGP key available from PGP public keyservers Coelacanth Engineering consulting & turnkey product development Middleborough, MA wireless * DSP-based instrumentation * ATE tel +1 508 947-8049 * fax +1 508 947-9118 * http://www.coelacanth.com/
Coincidentaly enough, this is part of my project for my Hardware class. I'll let you know when I have it working. I'm using Altera FLEX 81188s, though the 10K models (with built-in RAM) would be _way_ faster... - Ian
On 10 Apr 1996, Ian Goldberg wrote:
Coincidentaly enough, this is part of my project for my Hardware class. I'll let you know when I have it working. I'm using Altera FLEX 81188s, though the 10K models (with built-in RAM) would be _way_ faster...
Once someone gets this kind of cracking device ready, I think it would be nice to make the information freely available, or start selling these for nominal price. This would also make an interesting device connected to Internet. In case of fast device people could use it either for free or pay using ecash for using it, and crack their SSL sessions. May be Netscape or Microsoft or someone else (may be even Community Connexion :) lobbying the government for allowing export of strong encryption could sponsor it. It should not be so expencive. Much more useful than amazing fish-cam or coke machine on Internet. Juri Kaljundi jk@digit.ee
At 12:13 AM 4/9/96 -0700, Steve Reid wrote:
Is it really that easy to break 40-bit? Don't you need access to a "fair amount of cpu power" to brute force crack 40bit?
I remember reading a recent paper at this URL: http://theory.lcs.mit.edu/~rivest/bsa-final-report.ascii They mentioned a Field Programmable Gate Array (FPGA), specifically a board-mounted AT&T Orca chip available for around $400. They said it could crack a 40-bit key in 5 hours (average). Sounds like anyone with root access on a major internet node could make a significant profit stealing credit card numbers.
The FPGA sounds like a very interesting device, with quite a few legitimate uses... Has anyone out there seen one of these?
I was hoping a hardware type would answer this question, and give references to manufacture's spec sheets, but not having seen such an answer, here is a software person's answer.
I thought Perry Metzger's short answer (roughly "yes, but the software can be tricky") adequate, but as a hardware type I can give some more insight into the economics. While my experience is with gate array ASICs rather than field programmable chips, I have some idea. My short answer: Yes, it's that cheap, but only if you already work with the chip vendor and have the software tools to program the chips. If not, expect to spend many thousands of dollars buying engineering expertise and software. There's a lot of different ways to make chips for a custom application, which vary in unit cost, startup cost, engineering effort, and production time. Some points in the range: (costs are probably off a bit) type startup cost program design tool full custom $1000000 at design time schematic editors ASIC $100000 at design time gate synthesis FPGA $0 once vendor's tools reprogrammable FPGA $0 dynamically vendor's tools DSP chip $0 easily compiler General purpose CPU $0 very easily compiler Anyone who knows these better is welcome to correct me, of course. I've neglected software costs from this, which are significant. Chip synthesis tools are often more expensive than the workstations they run on. Also, in most cases some of the necesary tools are only available from the company that sells the chips. They tend to insist on nondisclosure agreements and software licenses, which makes anonymous production tricky. More design effort will give better price/performance. The appeal of the Orca and similar chips is that they can be reprogrammed, but still have the inherent parallelism of gates in silicon. I expect that in 5 or 10 years, PC's will come with reprogrammable logic chips and software that takes advantage of it. At present it really takes a trained engineer to use these things. That's just enough difficulty that people might feel secure, without actually being secure at all. Jon Leonard
"Jon Leonard" <jleonard@divcom.umop-ap.com> writes:
My short answer: Yes, it's that cheap, but only if you already work with the chip vendor and have the software tools to program the chips. If not, expect to spend many thousands of dollars...
Huh? We're talking about modern FPGAs here. The cost of the tools necessary to actually *program* the damn things is very small, as almost all of them are SRAM-based and programmed out of an external EPROM, bus, or serial bitstream. Sure, we've spent $50,000 on FPGA *development* tools, but we program the serial EEPROMs themselves on $300 PC-based programmers which are available -- as are the FPGAs and EEPROMs -- from Digikey, Allied, Newark, etc., to anyone with a credit card. Actually, in almost all of our designs, the FPGAs are programmed in-circuit by application software. If I were to design a hardware key cracker, it would almost certainly be a simple ISA-bus card containing a couple of big Xilinx FPGAs which would get programmed by a simple C program. [Funny thing -- there seems to be a lot of "theft" of satellite and cable programming by folks who know just enough to use a soldering iron, but haven't a clue about what really happens inside a set-top box. How do they manage it, if they don't have the tools to design or reverse-engineer a cable converter? Hmmm...] -- Roger Williams PGP key available from PGP public keyservers Coelacanth Engineering consulting & turnkey product development Middleborough, MA wireless * DSP-based instrumentation * ATE tel +1 508 947-8049 * fax +1 508 947-9118 * http://www.coelacanth.com/
participants (6)
-
Dave Emery -
frantz＠netcom.com -
iang＠cs.berkeley.edu -
Jon Leonard -
Jüri Kaljundi -
Roger Williams