Level 0

  • Clue: IyMjIyMjTlNRMjAxN0ZnbmVnLVBlbGNnYkFyamY=
  • The answer: ######AFD2017Start-CryptoNews decoding the clue with base64, and then rot13

Level 1

  • Clues: NFRHI4TENB4WC5DBMF2GWYY= | 1<<5
  • From 1<<5, participants were expected to arrive at base32
  • Decoding the first clue using base32 yields: ibtrdhyataatkc
  • Swapping each pair of letters results in ######birthdayattack

Level 2

  • Clues: Common Vulnerabilities and Exposures | Stocks
  • A quick Google search finds Cenovus Energy, of which the TSX and NYSE is CVE
  • The answer: ######CenovusEnergy

Level 3

  • Clues: 0154 0252 0158 0254 0236 0231 0239 0244 0250 0154 | ⎇ | http://i.imgur.com/hGNGTd8.png
  • Using the last two hints, people were expected to arrive at https://en.wikipedia.org/wiki/Alt_code
  • Looking up the alt codes results in šüžþìçïôúš
  • The answer: ######suspicious

Level 4

  • Clues: On light clouds of the upper zone, Pillows meet for our reclining, We may rest while day is shining. | https://i.imgur.com/XAyi8DY.png | CVE
  • The first clue is an excerpt of Nimrod, a poem by Robert William Jameson
  • The second clue consists of the logo of Avira, a security software company - and a trailing m
  • Nimrod Aviram was one of the original reporters of the DROWN attack
  • The answer: ######CVE-2016-0800

Level 5

  • Clues: 1487289600 - 1487894400 | answer is rot13'd
  • The first clue consists of two dates, giving a range in which the Cloudbleed bug was discovered and discussed
  • The answer, after applying the second clue: ######PybhqOyrrq

Level 6

  • Clues: https://is.gd/gGJ0T0 | Append "Schneier" to solution | Sigma | Ouroboros | reverse, apply |
  • The first URL points to an image of a whirlpool
  • Participants were expected to realized the connection between what the image portrays and the WHIRLPOOL hashing algorithm
  • Experimentation, or applying the last few hints, was expected to lead to people looking at the WHIRLPOOL hash of the image itself
  • The answer: ######facadeSchneier

Level 7

  • Clues: 31.198056, 121.336389 | https://is.gd/HJJX2m | Ш | Append "Blue" to solution | family
  • Each of the first three clues resolves to SHA
  • Three SHAs, or SHA-3
  • Hunting on wikipedia for SHA-3 was expected to lead people to Keccak, a cryptographic primitive family
  • The answer: ######keccakBlue

Level 8

  • Clues: Tq\uGTwqtt | Append "ShakeIt" to solution | pattern
  • Converting the first hint into a stream of bits results in morse code (in the form of 1-bits interspersed between 0-bits)
  • The answer, after applying the second hint: ######StubbornShakeIt

Level 9

  • Clues: ######quadrooter | sms | Международная организация по стандартизации
  • The quadrooter channel linked to the music video of Call Me Maybe
  • Players were expected to type quadrooter on a mobile phone keyboard
  • The answer: ######778823777666666833777

Level 10

  • Clues: https://is.gd/qLde0I | Hertz
  • The URL pointed to an audio file
  • Examining the spectrogram of said file was expected to make people realize they were looking at bytes
  • The least significant bit is represented by a frequency around 1.9kHz, whilst the most significant bit is represented by a frequency around 7.5kHz
  • Decoding the bytes as ASCII leads to: BerenstainBears
  • The answer: ######BerenstainBears

Level 11

  • Clues: https://is.gd/b9oNHn | free speech
  • Each colour of the flag corresponds to three ASCII characters (one per colour channel), plus a final character at the end
  • The answer: ######CouNTEriNtUiTIvE

Level 12

  • Clues: E7 D2 C3 C4 40 C3 D3 C9 C9 C9 | xkcd.com/927 | ♫
  • The bytes given as the first clue were expected to be interpreted as EBCDIC
  • This yields XKCD CLIII - https://www.xkcd.com/153/
  • The comic in question contains a reference to Missy Elliott
  • Players were expected to hit search engines and come up with...
  • The answer: ######WorkIt

Level 13

  • Clues: KPCfjoIzMiAtIENWRS0tKSArICjwn5Kp8J+QhCAtIENWRS0tKQo= | arithmetic
  • Decoding the first clue using base64 results in (🎂32 - CVE--) + (💩🐄 - CVE--)
  • The emoji hint at Sweet32 and Dirty COW
  • Corresponding CVEs are 2016-2183 and 2016-5195
  • Using the last hint, people were expected to add 20162183 and 20165195, resulting in...
  • The answer: ######40327378

Level 14

  • Clues: https://is.gd/VXqYzD | 字 | ローマ字
  • The linked picture is a nonogram - solving it results in the kanji 没: drown
  • The second and third clue (字: character/word, ローマ字: romanization) hint at the Japanese translation for drown
  • The answer: ######oboreru

Level 15

  • Clues: MSAyIDIgMSAxIDIgMiAyIDMgMCAxIDIKMiAzIDAgMyAzIDEgMyAxIDEgMyAyIDEKMiAwIDAgMiAyIDAgMiAwIDAgMSAwIDIK | touch | ⚅ | U+2800
  • Decoding the first clue using base64 yields: 1 2 2 1 1 2 2 2 3 0 1 2 2 3 0 3 3 1 3 1 1 3 2 1 2 0 0 2 2 0 2 0 0 1 0 2
  • Converting each number into binary form: 01 10 10 01 01 10 10 10 11 00 01 10 10 11 00 11 11 01 11 01 01 11 10 01 10 00 00 10 10 00 10 00 00 01 00 10
  • The last three hints were expected to lead people to try decoding the bits as braille
  • The answer: ######marc.stevens