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Random Numbers, CryptoFails & CryptoCurrencies

Explore the challenges of cryptography, random number generation, and cryptocurrencies. Learn about common crypto fails, side channel attacks, and the importance of encryption. Discover the world of RNG sabotage, Snake Oil cryptography, and the unusability of public keys.

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Random Numbers, CryptoFails & CryptoCurrencies

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  1. RandomNumbers,CryptoFails& CryptoCurrencies

  2. Cryptography is nightmare magic math that cares what kind of pen you use -@swiftonsecurity

  3. Announcements!

  4. In Practice: Session Keys...

  5. How to prevent a MitM attack?

  6. Signatures EnableEphemeral Diffie/Hellman

  7. Exercise:Send me an encrypted message

  8. Cryptofail: MAC then Encrypt or Encrypt then MAC?

  9. Cryptofail: MAC then Encrypt or Encrypt then MAC?

  10. Padding Oracle Attack

  11. The TLS 1.0 "Lucky13" Attack:"F-U, This is Cryptography"

  12. CryptoFail:Side Channels

  13. A Lot of Uses forRandom Numbers...

  14. Breaking Slot Machines

  15. Breaking Bitcoin Wallets

  16. TRUE Random Numbers

  17. Combining Entropy

  18. Pseudo Random Number Generators(aka Deterministic Random Bit Generators)

  19. Properties for the pRNG

  20. Prediction and Rollback Resistance

  21. Why "Rollback Resistance" is Essential

  22. More on Seeding and Reseeding

  23. Probably the best pRNG/DRBG:HMAC_DRBG

  24. HMAC_DRBGUpdate function hmac_drbg_update (state, input) { state.k = hmac(state.k, state.v || 0x00 || input) state.v = hmac(state.k, state.v) state.k = hmac(state.k, state.v || 0x01 || input) state.v = hmac(state.k, state.v) }

  25. HMAC_DRBGGenerate function hmac_drbg_generate (state, n, input) { tmp = "" while(len(tmp) < N){ state.v = hmac(state.k,state.v) tmp = tmp || state.v } if input == null { // Update state with no input state.k = hmac(state.k, state.v || 0x00) state.v = hmac(state.k, state.v) } else { hmac_drbg_update(state, input); } // Return the first N bits of tmp return tmp[0:N] }

  26. UUID: Universally Unique Identifiers

  27. What Happens When The Random NumbersGoes Wrong... http://blog.dieweltistgarnichtso.net/Caprica,-2-years-ago

  28. And Now LetsAdd Some RNG Sabotage...

  29. Well, anyone not paid that is...

  30. But this is insanely powerful...

  31. It Got Worse:Sabotaging Juniper

  32. Sabotaging "Magic Numbers"In General

  33. Because Otherwise YouHave Trouble...

  34. Snake Oil Cryptography:Craptography

  35. Anti-Snake Oil:NSA's CNSA cryptographic suite

  36. Snake Oil WarningSigns...

  37. Lots in the Cryptocurrency Space…

  38. Snake Oil WarningSigns...

  39. Unusability:No Public Keys

  40. Unusability:PGP

  41. Unusability:How do you find someone's PGP key?

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