type of encrytpion used

Question

did you know the type of encryption/encoding use to encode this data

q4j4k58416u5g4k5j413x213d414c4z2o254m4c3f4i5f5k4j5h4e5f4m52393q4d3s373f2i3e3x3a3s4m305m30565u3w4i3z2m4s4m5m5m573h344a4r254b4b4w2e4p4m574462354m5d443m4m4h4e4k463m5w5g5n416e4a3n4i3n383g2u4i495b3c3n3z4k3z46535n3s4

second

q4j4k58416u5g4k5j413x21364846403q274p4e3f4i5f5k4j5h4e5f4m523h355d3a3h3c3e2n3f3l3t4u4m4t3p3y4d3o4y3d3l3n3n4c416q444o5k543x44484u254s254z2g4n4d4n5n46334b4j483q4k4r5j5v563n5x544x5p4z2g3v3v4i4x4b382t4p4j3t4v4j4u3n3m3l4b3a5e3m3x453

thanks in advance

Answer 1

Like J.A.K. said, its some type of custom encryption, and a poor one at that. Given enough content and or an example of what a given piece of clear text would be encoded as it could be cracked by multiple people here.

Things that I noticed:

• characters a-z 0-9 are used (makes me think Caesar cipher)
• character frequency does not match english, but could reasonably be another Latin based language or simply contain filler to throw people off.
• Two blocks given both start with the same "header" q4j4k58416u5g4k5j413x213 this could be a 'Heil Hitler' see Enigma Cracking, or a key of sorts for decryption.

In any regard, whoever is using this encryption broke the cardinal rule "dont roll your own" ... and it is very likely it will be cracked if it is being used commercially.

Answer 2

Seems like someone rolled their own.

It's probably a simple 2 byte encoding/substitution; the strings are the same up to 'm523', implying a header. The format is [char/int][int]. The distribution of the left value is consistent with the 26-10 you'd expect. Chars mostly m or n .The right hand value is mostly 3,4 &5; leaning to the lower side.

The uneven distribution makes me think this is the only security used and not too hard to bruteforce. Strong ciphertext would always be more varied. Further analysis is left as an exercise. But the answer is; it's custom. And probably another example of why writing your own is often a bad idea.