Secure Prop Module

mctrivia · 2009-02-22 07:55

I am building a wide 40 pin dip(2"x0.8") prop module. I have designed 2 different models and I was wondering if any was interested in either of them. Both Modules include propeller, 5Mhz Crystal, programing head, and a fusible security system to prevent end user from being able to read or modify your code. The pins have been layed out so they can be used in a standard bread board. The prop, eeprom, and Real Time Clock(RTC) are encased in resin. All pins except P29 are accessible through the header. P31 is not accessible after the code security option has been activated. I need to make at least 10 for cost reasons but can sell base model for $50CAN(About $41 US at the moment). Can ship by your preferred means at cost. I should have the prototypes done Tuesday and if they work can start shipping in 2 to 3 weeks.

Model 1:
*512Kb EEPROM(double the amount needed for prop)
*5MHz Crystal
*Prop
*RTC with rechargeable lithium battery(optional $10 extra)
*1A Switching power supply($20 extra)

Model 2:
*512Kb EEPROM(double the amount needed for prop)
*5MHz Crystal
*Prop
*RTC with rechargeable lithium battery(optional $10 extra)
*Micro SC Card Reader(optional $2 extra)

Tubular · 2009-02-22 11:41

hi mctrivia,

I'm interested in Option 2 with the Micro SD. Its for an existing low volume industrial application. Please put me down for 2 as initial samples. I don't mind with or without RTC, whatever works for your batch.

Are the I/O pins still on the standard 0.6" pitch? If so it would slot right in to my existing pcb

regards
tubular

mctrivia · 2009-02-22 16:57

bread board pin pitch is 0.1" also this package is slightly different pin out but if vertical height is not a problem for a temporary fix an adapter board could be easily made. Pins can be in order of the layout below or I can put the header in upside down and flip the pins around. The fliped orientation would be recommended for the uSD card if you want people to see it otherwise the uSD would be on the bottom of the module though still accessible.

The uSD card if used uses P0-P3 as in examples in SD fat16 object

It makes no difference to me if the RTC is on or off. The RTC can not be added later though so if you think you want it then I recomend getting it.

VDD and Vin are connected on SD Module.

Post Edited (mctrivia) : 2/22/2009 5:03:35 PM GMT

mctrivia · 2009-02-23 00:46

Tubular I was looking at the dlp-prop and realised that by pitch you mean distance between rows. My module is 0.7" pitch. I could probably squeeze it down to 0.6" by changing to smt legs if the extra width is an issue for people.

I will be making adapter board designs tonight for both the dlp-prop and the 40pin dip propeller so you do not have to change the design to test it out.

Tubular · 2009-02-23 03:16

Ok. If you're already doing some kind of adapter to DIP40, great, I don't even have to think...

Longer term, if its a goer, we would adapt the mating PCB to match up with your standard 0.7" design.

tubular

mctrivia · 2009-02-23 03:58

I want to make it as easy and as useful for everyone.

rjo_ · 2009-02-23 04:10

It will certainly be easy and useful.

If you decide to do it...I'd take two.

I don't need a clock. I like the 1 Amp switching power supply.

mctrivia · 2009-02-23 04:54

Well the uSD version is a go ahead. I need 6 for myself and Tubular said he wanted 2 so I can eat the cost of 2 extra till some one else wants them.

The switching supply I can make as a separate module with low power loss battery switch over if not enough are interested with it on the module.

mctrivia · 2009-02-23 06:30

I made a small error on the pcb layout for the adapter. Here is the corrected. You can chop off the pins to the left of board they give you access to Vbat, Clock Out which are only used if using RTC. Vbat is only needed if you chose to use a different battery then the normal 9mm. Also gives you access to Vin which is only on the Power Supply Version.

The header row slightly shifted left is for the prop module and should be female on top or soldered directly to prop module.

The header row slightly shifted left should be male pins below board and align with the standard prop package.

Pin 1 for each is on the bottom left.

I can get the boards made in quantity of 2 for $10CAN(each) or you can make them yourself.

Post Edited (mctrivia) : 2/23/2009 6:35:19 AM GMT

mctrivia · 2009-02-24 06:53

Well I got the prototype in and up until I destroyed it by applying 9v(uSD version) it was working perfectly. I have parts and can assemble and ship 4 of the uSD version by Monday March 2nd. There will be more to come after that when I can get the propellers in.

please pm me with address to ship modules to.

mctrivia · 2009-02-24 07:00

also please tell me if you want adapter board. Cost $10 for board male pins are $3 if you need(don't have female sockets)

Just a warning adapter boards from me come with no solder mask, or silk screen.

SRLM · 2009-02-24 07:37

Can you post pictures?

Drone · 2009-02-24 11:06

Mctrivia said...
and a fusible security system to prevent end user from being able to read or modify your code

Can you explain how this works? It seems to me if anything is encrypted what it takes to decrypt it must be downloaded from the ROM "in the clear" first during the bootstrap process. This would make it subject to a sniffing man in the middle. Hmmm...

Regards,

David

mctrivia · 2009-02-24 14:28

this works on the principle of not allowing physical access to the data.

How can you access the data on the prop?

1) if you have access to the SDL and SCL from the eeprom you can download it direct
2) if you have access to the prop RX and TX you could load a program in ram that sends the eeprom contents back to you

With this module there is no way to access the SDL from the EEPROM because the board is encased in epoxy. You can access RX and TX to program the module but once you are done you can blow out a fuse removing access to RX by following these steps:

1) remove power
2) shoring VDD and VSS
3) apply power source positive lead to VSS(outside pins of programing header), negative lead to RX(middle pin of programing header)

as long as the power source can provide at least 250mA it will blow a fuse making it now inpossible to reprogram the module. Your data is secure.

dMajo · 2009-02-24 18:28

mctrivia,
am I drunk ?

I have opened this thread, but due to business i was not able to read it immediately. I have seen some pictures and when I clicked on them I received access denied

I have refreshed the ie page and ... and ... no more pictures?

... maybe is time to have a coffe-break ...

mctrivia · 2009-02-24 19:28

sorry I need to put new ones up. will do in about 6 hours

mctrivia · 2009-02-25 03:15

pictures

Oldbitcollector (Jeff) · 2009-02-25 03:25

Very clever..

OBC

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?

Check out: Protoboard Introduction , Propeller Cookbook 1.4 & Software Index
Updates to the Cookbook are now posted to: Propeller.warrantyvoid.us
Got an SD card connected? - PropDOS

mctrivia · 2009-02-25 03:29

thanks. Now off to make a few more adapter boards. I love Brian's Spin Studio so I will work on an adapter board to allow use of his modules next.

mctrivia · 2009-02-26 03:26

Well I got the boards back together today and have a program running on the first of the moduals assembled. Will figure out how to make a video and make link when I am done.

here is the eagle package file for the sd module. note that in normal orientation there are a few locations noted in tdocu layer that you must keep clear of parts otherwise though you should be able to place parts underneath the module.

mctrivia · 2009-02-28 05:24

well the first batch is done, tested and working. They come preloaded with

CON

  _clkmode      = xtal1 + pll16x
  _xinfreq      = 5_000_000
  
OBJ
    SD  : "FSRW"

PUB start |i
  i:=sd.mount(0)
  if (i<>0)
    repeat

  dira:=$dfff_fff0                   
  outa:=1
  repeat
    outa:=outa<<1
    if outa==0
      outa:=1  
    waitcnt(cnt+clkfreq/8 )

registered http://www.propmodule.com/ but the dns does not seem to point to my server yet.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Need to make your prop design easier or secure? Get a PropMod $50CAN has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module.

Jo · 2009-02-28 06:00

Hmm, you keep using the word "secure". I don't think that word means what you think it means.
This is not secure; at best it is slightly inconvenient for somebody with nefarious purposes.
As someone previously pointed out, epoxy != security.
Secure means that it should be resistant to attack to someone if physical possession of the module.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
---
Jo

mctrivia · 2009-02-28 06:03

well it is true it is not 100% secure. This is not possible ever.

You can not download the contents of the eeprom with out first cutting through the epoxy. That really is the best that can be done with the prop.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Need to make your prop design easier or secure? Get a PropMod $50CAN has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module.

mctrivia · 2009-02-28 06:10

also thought the purpose to develop it was code security it is also a very convenient package. small and contains all the essential parts except a voltage regulator(and that can be done if enough are interested to get the minimum 10 required to build for quoted price.)

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Need to make your prop design easier or secure? Get a PropMod $50CAN has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module.

mctrivia · 2009-02-28 06:26

trying to make even more secure and block x-rays. Anyone know anything about getting tin shielding? Were I can get if it will block? ect

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Need to make your prop design easier or secure? Get a PropMod $50CAN has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module.

mctrivia · 2009-03-01 05:31

Writing up some documentation. Any suggestions on what more information is needed?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Need to make your prop design easier or secure? Get a PropMod $50CAN has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module.

heater · 2009-03-01 06:17

X-rays - This module is going to get very heavy.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
For me, the past is not over yet.

mctrivia · 2009-03-01 06:20

well i don't want to make it heavy. if i could get some kind of container to hold in the resin I could do 2 layers. 1 to protect and electrically insulate. another with metal filings or something to make x-rays harder to interpret.

any ideas on either? right now my bigest problem is keeping the resin from spilling over the board edges but still being thick enough to obscure position of ics. requires a lot of babysitting.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Need to make your prop design easier or secure? Get a PropMod $50CAN has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module.

heater · 2009-03-01 06:48

It's not worth pushing this security idea any further.

A quick dip in DYNASOLVE 165 soon has the thing de-potted ready for sniffing or reprogramming.

www.dynaloy.com/Products/tech_data_sheets/Dynasolve%20165%20PDF.pdf

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
For me, the past is not over yet.

mctrivia · 2009-03-01 06:58

well unfortunately it is illegal to pack explosives around the eeprom that go off when tampering is detected(works great though).

still I can just make it as secure as possible and hope it is not worth the bother.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Need to make your prop design easier or secure? Get a PropMod $50CAN has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module.

Tubular · 2009-03-01 07:43

"Dynasolve 165 is not selective and will attack most thermoplastic
materials, wire coatings, and many thermoset coatings and materials. It will also discolor and etch aluminum."

I wonder how much of the eeprom would be left after a long bath in such a solvent. Heater do you have any of this solvent to try this?

From the datasheets what they don't tell you is how long the solvents take to break down the bonds. In my experience with a similar solvent its a couple of weeks (100x50x12mm), perhaps quicker with agitation and/or scraping.

Anybody know what happens to these solvents when applied to lithium batteries?

tubular

Secure Prop Module

Comments