Keygens, Protection, Encryption Panel Software Protection Methods (SIC

1
Keygens, Protection, Encryption PanelSoftware
Protection Methods (SIC 2003)

• Chris Thornton
• Thornsoft Development, Inc.
• chris_at_thornsoft.com
• www.thornsoft.com/sic.htm

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Anti-Piracy Concerns

• The crackers will still crack you. Thats just
  the way it is.
• Strong encryption helps - but a dedicated,
  skilled cracker can eventually get in. (We used
  to be cracked within days of a new release - now
  its months.)
• Use secondary defenses (integration) with any
  wrapped solution.
• With strong encryption, expect to see more CC
  fraud, and keys passed around on the net.

3
Strategy

• Use blacklisting to lock out stolen keys.
• Use Partial Key Verification to detect forged
  keys. (Absolutely necessary if you dont use
  strong encryption.)
• In both cases, dont simply quit the program.
  Youve got a potential customer here - try to
  sell them.
• Goal Make the crack experience less enjoyable.

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Blacklisting
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Piracy Marketing

• DaRkAnGeL appears in 4 threads on usenet.
• 4,500 visits to my naughty pirate since
  blacklisting in May.
• We tracked 96 of those visits to the order page,
  using cookies.
• We answered 26 how do I get around the piracy
  message to enter my new key? requests by e-mail,
  and 20 more by phone.
• The error 411 page is currently ranked 8 out of
  our about 90 FAQ pages, with 460 hits.

6
Partial Key Verification

• Dont give the cracker enough information to
  build a complete key.
• They can only build a keygen against what they
  see in the program. So, leave some of the checks
  out, and add them back into future releases.
• Each release only checks part of the key (Details
  on next slide)
• Each release of your software requires crackers
  to make a new keygen.
• Users arent impacted, as their keys have all
  correct digits.

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Example of obsolete keygen.
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The Mechanics

• I use If SampleKey UserKey then
  RegisteredTrue algorithm. (standard stuff)
• To generate the SampleKey, first, I generate 10
  decoy digits, from the users name.
• Ex for i 0 to 9 do RegKeyi
  (Ord(CleanStringi) 2) Mod 10
• Then, in the positions that Im actually
  checking, I overwrite the decoys with digits
  generated by the actual algorithm, leaving decoys
  in the unchecked digits.
• Ex RegKey7 ((Ord(CleanString1)3) -
  Ord(CleanString4)) Mod 10

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Mechanics (cont)

• In the previous example, the middle 5 digits are
  not checked. I dont check the decoys.
• In the next release, Ill add another digit, and
  take one more away. Forged keys can now be
  detected.
• Forged keys launch an URL to our error 511
  page, which logs their IP address, the name/key
  that was used, and the date/time.
• But my customers keys, generated with all
  correct digits, will be just fine.

10
PKV with Strong Encryption

• Strong encryption (RSA, Armadillo, ASProtect,
  etc.) usually encrypts some information about the
  user, hardware, etc.
• Add another layer inside, so that in case the
  main gate is breached, you still have your
  secondary key within a key to use with PKV.
  Like an onion.

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PKV Example

• my_pkv(chris thornton) 10011101
• Encrypt (chris thornton 10011101) with
  strong encryption (RSA, ARM, ASProtect, etc.)
• In the program, you have the whole 10011101
  sequence - but only check a couple of the digits.
  
• Next version, check another digit. Now youve
  got PKV within a stronger package, and the
  cracker can never build a complete keygen without
  a crystal ball.