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semi-invasive [2018/02/25 09:15] mcmastersemi-invasive [2019/12/08 19:23] (current) mcmaster
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-====== Photonic (UVEPROM erase ======+====== UV EPROM erase ======
  
 EPROM/EEPROM/flash can be erased by shining UV light or x-rays into the surrounding oxide. This slightly oxidizes it, letting the floating gate to drain out. EPROM/EEPROM/flash can be erased by shining UV light or x-rays into the surrounding oxide. This slightly oxidizes it, letting the floating gate to drain out.
 +
 +Usually a masking compound is applied to selectively block UV to the firmware, with red nail polish being the most popular or at least traditional.
 +
 +{{:mcmaster:nail_polish:overview.jpg?400|}}
 +
 +McMaster misc notes
 +
 +Application
 +  * Use a single hair brush
 +    * Ex: cut down MG 855-5 horse hair brush
 +  * Place chip in bowl
 +  * Shallow fill bowl with acetone
 +    * Creates shield gas to prevent nail polish drying out in small quantities
 +    * Place paper towel on side to elevate gas enough to keep nail polish liquid
 +  * If nail polish is too viscous, slightly set top of chip with IPA
 +  * Apply a glob of nail polish, then use the spring force of the liquid to precisely move it around
 +    * By gently agitating the liquid boundaries its possible to very precisely move it forward
 +  * Place the nail polish in the bowl in some sort of holder
 +    * Ex: above image has a 1/4-20 SHCS with a nut screwed on as a base
 +
 +Nail polish
 +  * [[https://www.amazon.com/gp/product/B00LT8S30G/|Revlon ColorStay Gel Envy Longwear Nail Enamel, Queen of Hearts]]
 +  * Also can be used to look fabulous!
 +  * Bought at local store a while back and it seems to work well enough
 +  * Other colors probably fine, but red is easy to see
 +
 +{{:mcmaster:nail_polish:pipette.jpg?400|}}
 +
 +Above: fine polypropylene tip for more aggressive cleaning. The tool is strong enough to damage bond wires though, so use sparingly
 +
 +Nail polish removal
 +  * Bulk removal with acetone, but leaves some residue around edges
 +  * Remaining residue softened with acetone
 +  * Remove using single hair brush if possible
 +  * Can be more aggressive with PP monofilament wire
 +  * Cold H2SO4 also works well. Wash with IPA then acetone
 +    * Washing with water may really heat up the mixture
 +
  
 ===== Angle ===== ===== Angle =====
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-====== Non-invasive attacks ====== +====== X-ray EPROM erase ======
- +
-[[jtag|JTAG]] +
- +
-[[ripping|Ripping firmware]]+
  
-[[dpa|Differential power analysis]]+TODO: add links to misc papers
  
  
 
semi-invasive.txt · Last modified: 2019/12/08 19:23 by mcmaster
 
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