DEF CON 28 Badge Hacking

Join the fun and help solve the puzzles of the audio cassette badge

Public Chat
Similar projects worth following
Let's work together to solve the challenges of the DEF CON 28 badge.

DEF CON Safe Mode is happening virtually this year, from August 6-9, but they still offered a badge for purchase, packed with puzzles by 1o57, DEF CON's puzzle master

First look at the badge was published on

How to get involved:

  • There's a public live-chat for this project. Join in by clicking the button on the upper right.
  • If you want write access to project logs and description on this page, click the "Join this project's team" button in the left sidebar.

Details of the badge:

A dump of the audio contents is available at the Internet Archive

Hi-res scans of the liner notes:

Here are some images:


high quality scans of liner notes

Adobe Portable Document Format - 18.32 MB - 07/31/2020 at 20:40


Defcon A1.wav

Track A1 from Defcon media server, drop me in an oscilloscope!

Waveform Audio File Format (WAV) - 33.15 MB - 07/25/2020 at 05:31


Defcon B6.wav

Track B6 from Defcon media server, drop me in an oscilloscope!

Waveform Audio File Format (WAV) - 24.64 MB - 07/25/2020 at 05:31


DC28 - Lanyard Symbols.png

Lanyard symbols, numbered based on order of appearance in this orientation. Symbols 1 / 9 and 4 / 8 are flipped copies; however, rotating the blocks they appear in doesn't seem useful for reducing the number of symbols

Portable Network Graphics (PNG) - 1.13 MB - 07/24/2020 at 21:17


  • Lanyard Hint

    psmitty08/04/2020 at 20:08 0 comments

    This tweet is apparently directed at the lanyard:

    Google translate yields:

    Korea is divided into north and south. They speak the same language and have the same customs. And, it's the same people. It must be peacefully unified. To do that, we need to have a conversation with each other. That is the way to live. “I love each other”

    Possible the top halves of the lanyard need to in fact be AND/OR/XOR/something'd.

  • psmitty7373 Has solved the other text from the sleeve

    gr4n1t307/29/2020 at 17:23 1 comment

    The l (elle) was in fact an upper case I (eye)
    ""  I believe tlstFCOnRFoofFioumYrgureoohrDOuntlon is a route transposition and decodes to the message "ComeOnFourDotForIsRightInFrontOfYou"   ""
     t     I   s   t  F  C  O   n   R   F   o  o    f   F   i   o  u  m  Y   r   g    u  r   e   o   o   h   r  D  O  u   n    t    I   o  n  
     31 25 19 13 7  1  32 26 20 14  8  2  33 27 21 15 9  3  34 28 22 16 10 4  35 29 23 17 11  5  36 30 24 18 12 6
     t  l  s  t  F C
    O n R F o o
     f  F  i  o u m
     Y r  g u  r e
     o o h  r D O
     u n  t  l  o  n

    *Edit formatting

  • Transcribing 1o57 ciphers from liner notes

    Mike Szczys07/24/2020 at 20:11 3 comments

    Here are the dumps of messages from 1o57 in the liner notes:

    Xbaw maek wzme pgty zvxy izwk iwhk lnhy
    agrl rrlp fsis xadh uflx dsqh rzrg qegu
    itwb wveq aslo moii xmzx mvea rtil yekd
    lvks jrbo arvy nmjz wodi gcxe tkrr cyir
    xbsu rwyf slwr ixyk lrwz sbzr zbpg rrrw
    hjsi alXX 1o57

    There is a possibility that the lower case L that I used in these is actually an upper case I.

    Update: @Lord Kiba has found one solution for this:

    What's up people!
    I believe I solved the transcribed text from cassette case it's a keyed Vigenere Cipher
    Decoded text is as follows "Know that as in life there is much that many have looked upon but few have seen because as my father told me and his father told him you will come to learn a great deal if you study the insignificant in depth "

View all 3 project logs

Enjoy this project?



hlew wrote 08/05/2020 at 22:14 point

I was looking at solutions from previous year especially DefCon 23. It looks like 1057 uses ROT13 with a Ceasar substitution Cypher each year. It look you have found the incident when you decyphered the audio numbers.

  Are you sure? yes | no

hlew wrote 08/05/2020 at 22:10 point

Some one mentioned on DefCon forums that the first letter of the name of the tracks on Side A spell out "LOSTINTIME" or LOST IN TIME.  May or may not be a clue for one of the other challenges.

1057 uses a lot of cultural reference which I usually miss.

Just starting to look at the content. Being international it looks like my actual physical badge will not arrive in time so I am going by the content online.

  Are you sure? yes | no

monitoor wrote 08/04/2020 at 01:48 point

So on Side A at about 3:38 you have/hear the following numbers

15 18 6 8 5 18 7 2 17 5 22 1 24 12 2 8 5 2 9 14 25 7 22 1 18

they are an A1Z26 Cipher, which translates to


Then take that and push it through a ROT13 conversion you get


EDIT - Didn't see ejhokan's Post until after I hit submit. 

  Are you sure? yes | no

ejhokan wrote 07/28/2020 at 20:36 point

If you look at the track listing for side A, you will see "Substitution Cipher" as one of the tracks.  At 3:38 in you hear the following numbers: 15 18 6 8 5 18 7 2 17 5 22 1 24 12 2 8 5 2 9 14 25 7 22 1 18.  I won't spoil it for you but it is a straight substitution cipher.  Think decoder ring ;)

  Are you sure? yes | no

Geoff Mitchell wrote 07/26/2020 at 15:29 point

thats awesome. The answer was right there the whole time.

  Are you sure? yes | no

pelrun wrote 07/25/2020 at 02:42 point

The colour blocks on the outer spine are obviously "DEF CON SAFE MODE", therefore:

D red (4)
E blue (5)
F pink (6)

C purple (3)
O green/blue (15)
N green/red (14)

S green/dark blue (1/9)
A green (1)
F pink (6)
E blue (5)

M green/purple (1/3)
O green/blue (1/5)
D red (4)
E blue (5)

Then the inner spine decodes to:

D red (4)
I dark blue (9)
V yellow/yellow (2/2)
O green/blue (1/5)
C purple (3)

O green/blue (1/5)
O green/blue (1/5)
B yellow (2)

(took me more than a few minutes to realise I had this backwards: BOO COVID)

  Are you sure? yes | no

Mike Szczys wrote 07/25/2020 at 02:45 point

Nice work!

Iadded you to the team so you can add and edit pages. If it's a page you didn't create you should be able to edit by adding /edit to the project log url.

  Are you sure? yes | no

Alexander wrote 07/25/2020 at 18:35 point

Heh, yeah, when I first looked at it I thought it might be ROT-13 or something. Nope, just backwards :D

  Are you sure? yes | no

CN=Your Identity Hero, OU=BLM wrote 07/29/2020 at 01:17 point

Yeah, Decoder Ring already used ROT-13. =)

  Are you sure? yes | no

Similar Projects

Does this project spark your interest?

Become a member to follow this project and never miss any updates