5 ms·

Crystal Pattern Matching Recovers Serial Numbers Obliterated from Metals

42 points by ledgeditor 12y ago

mschuster91 12y ago
Sounds certainly impressive, but can't this analysis be stopped/manipulated by simply stamping another serial number or a dot-matrix pattern over the original serial? And what happens when the area is heated, e.g. with acetylene, short before melting point?
- pavel_lishin 12y ago
  It might not help going forward, but I'd wager it'll help close a few cases in the meanwhile.
  - mschuster91 12y ago
    Honestly I don't understand how utterly stupid criminals can be. Especially guys who planned the crime. I'd say that being the son of a cop has its advantages in life ;)
    - pavel_lishin 12y ago
      I... am not sure what you mean.
      - pixl97 12y ago
        $meaning = decode_string("I\'d say that being the son of a cop has its advantages in life \;\)" ; print $meaning; "They will never find the bodies."
        mschuster91 12y ago
        > "They will never find the bodies." Heh, if I were on the run for murder the last thing I'd do is post stuff on the interwebs under real name. Especially not these days, when everyone and their dog can track each other (hello, SS#7)... But I'd say the likelihood of me getting robbed or scammed is lower than the average...
        Retra 12y ago
        That's what someone one the run for murder would want us to think...
        mschuster91 12y ago
        Murder is one of the most stupid crimes to commit - according to Wikipedia, 97.6% of all murder cases are solved.
      - fiatmoney 12y ago
        For instance, law enforcement in the great state of California is exempt from most restrictions on purchasing handguns, particularly the laws on "unsafe" handguns (which, quelle surprise, encompasses nearly every major manufacturers' latest and most popular models). They are further allowed to give or sell them to whomever they like, including presumably their kids.
- kleer001 12y ago
  Absolutely some people will adapt with this new knowledge. But I bet that many won't, as they'll have no idea. Not security through obfuscation, but security through people who're trying to cheat being ignorant of the hoops they have to jump through.
- NoMoreNicksLeft 12y ago
  I don't think heat treatment works... tends to change the hardness of iron-based alloys too much, often a big deal for a firearm (less clear though, whether it's relevant to VINs).
- PhasmaFelis 12y ago
  A lot more criminals have access to a $2 file than can get their hands on a stamping machine, or even an acetylene torch. Anything that raises the bar is a net positive.
  - wycx 12y ago
    Perhaps as many criminal have access to a punch or a chisel plus a hammer as have access to a $2 file.
sfeng 12y ago
Acids and etching solutions have been used to do this for many years. It takes longer, hence the relevance of this discovery, but it does often work long after the numbers are obliterated visually. My understanding is, similar to this method, it relies on the structural changes made in the underlying metal when the upper layers are stamped. It goes to show you just how tricky materials engineering must be, seeing how the structure of a material can be so easily changed in an invisible way.
- NoMoreNicksLeft 12y ago
  So keep grinding even after the serial's no longer visible?
  - iwwr 12y ago
    Or re-anneal the materials in an oven?
    - TrainedMonkey 12y ago
      Putting parts of firearms in the oven, does not sound like a safe thing to do if you are planning to fire from them afterwards.
      - busterarm 12y ago
        But totally the right thing to do with firearms you're trying to dispose of.
    - Crito 12y ago
      I wonder if peening might be sufficient. http://en.wikipedia.org/wiki/Peening http://en.wikipedia.org/wiki/Peening
  - MichaelGG 12y ago
    I'd imagine it might be more important to apply the same type of pressure as the stamping process. Assuming there's some maximum compression or structural change that can happen?
themoogle 12y ago
why not change the metal with say a quick spot weld or smack it with a nail and hammer randomly or small chisel? I wonder if a simple brazing rod would screw this recovery technique
sandworm 12y ago
Are all serial numbers stamped? I would imagine that some might be cut in. Laser? I presume that such numbers wouldn't create the changes needed for this technique.

42 points by ledgeditor 12y ago

Sounds certainly impressive, but can't this analysis be stopped/manipulated by simply stamping another serial number or a dot-matrix pattern over the original serial? And what happens when the area is heated, e.g. with acetylene, short before melting point?

pavel_lishin 12y ago
It might not help going forward, but I'd wager it'll help close a few cases in the meanwhile.
- mschuster91 12y ago
  Honestly I don't understand how utterly stupid criminals can be. Especially guys who planned the crime. I'd say that being the son of a cop has its advantages in life ;)
  - pavel_lishin 12y ago
    I... am not sure what you mean.
    - pixl97 12y ago
      $meaning = decode_string("I\'d say that being the son of a cop has its advantages in life \;\)" ; print $meaning; "They will never find the bodies."
      - mschuster91 12y ago
        > "They will never find the bodies." Heh, if I were on the run for murder the last thing I'd do is post stuff on the interwebs under real name. Especially not these days, when everyone and their dog can track each other (hello, SS#7)... But I'd say the likelihood of me getting robbed or scammed is lower than the average...
        Retra 12y ago
        That's what someone one the run for murder would want us to think...
        mschuster91 12y ago
        Murder is one of the most stupid crimes to commit - according to Wikipedia, 97.6% of all murder cases are solved.
    - fiatmoney 12y ago
      For instance, law enforcement in the great state of California is exempt from most restrictions on purchasing handguns, particularly the laws on "unsafe" handguns (which, quelle surprise, encompasses nearly every major manufacturers' latest and most popular models). They are further allowed to give or sell them to whomever they like, including presumably their kids.
kleer001 12y ago
Absolutely some people will adapt with this new knowledge. But I bet that many won't, as they'll have no idea. Not security through obfuscation, but security through people who're trying to cheat being ignorant of the hoops they have to jump through.
NoMoreNicksLeft 12y ago
I don't think heat treatment works... tends to change the hardness of iron-based alloys too much, often a big deal for a firearm (less clear though, whether it's relevant to VINs).
PhasmaFelis 12y ago
A lot more criminals have access to a $2 file than can get their hands on a stamping machine, or even an acetylene torch. Anything that raises the bar is a net positive.
- wycx 12y ago
  Perhaps as many criminal have access to a punch or a chisel plus a hammer as have access to a $2 file.

sfeng 12y ago

Acids and etching solutions have been used to do this for many years. It takes longer, hence the relevance of this discovery, but it does often work long after the numbers are obliterated visually. My understanding is, similar to this method, it relies on the structural changes made in the underlying metal when the upper layers are stamped. It goes to show you just how tricky materials engineering must be, seeing how the structure of a material can be so easily changed in an invisible way.

NoMoreNicksLeft 12y ago
So keep grinding even after the serial's no longer visible?
- iwwr 12y ago
  Or re-anneal the materials in an oven?
  - TrainedMonkey 12y ago
    Putting parts of firearms in the oven, does not sound like a safe thing to do if you are planning to fire from them afterwards.
    - busterarm 12y ago
      But totally the right thing to do with firearms you're trying to dispose of.
  - Crito 12y ago
    I wonder if peening might be sufficient. http://en.wikipedia.org/wiki/Peening http://en.wikipedia.org/wiki/Peening
- MichaelGG 12y ago
  I'd imagine it might be more important to apply the same type of pressure as the stamping process. Assuming there's some maximum compression or structural change that can happen?

themoogle 12y ago

why not change the metal with say a quick spot weld or smack it with a nail and hammer randomly or small chisel? I wonder if a simple brazing rod would screw this recovery technique

sandworm 12y ago

Are all serial numbers stamped? I would imagine that some might be cut in. Laser? I presume that such numbers wouldn't create the changes needed for this technique.