(Re)Introduction to passcode solving
We encourage all new Agents to learn cryptographic principles, some of which we have published in a series of posts:
If you’re actually interested in solving them, click the links and give them a try without the solutions.
The following codes are now Fully Redeemed:
6zh6codep8t4z 8xc2substitutionz4t7p 8ye3transpositionu2p9y 6qd7cryptoz4u8s 4zh4cipherz4s8v
The passcodes are in the following format:
The post suggests to increase the contrast and decrease the brightness of the image to reveal the code:
Looking at the bottom, we see something very faint:
Looking at the bottom of the image we see the substitution key. The long row of black symbols are the letters a to z, the row of black symbols just above that are the numbers 0 to 9, matching them up to the first two rows:
The first link describes the Railfence cipher and presents a code that has been encoded with it:
Using the Rumkin website to aid us with railfence, Decrypting the cipher text with 3 rails:
The second link describes some other types of transposition and presents us with a 16 character block on the left:
4u8s zotp 7cry dqiv
The transposition used for this one is boustrophedon (snaking) from the top-right corner and reversal:
But that doesn’t produce a valid passcode yet! The passcode format is almost correct except the first part, which needs to start with a number. vi is the roman numeral representation of 6.
The last link has an image with a child’s writing of the cipher text:
The hint is subtlely inserted as 4 but the method to use is not railfence. After going through all the methods introduced in the second link, the proper method is skip (4):
For the next post, we’ll be looking at the post that Verum Inveniri made after assembling the nominus dead drops and we’ll be revealing 3 more passcodes.