A Reddit user has posted an encrypted note he found in a family member’s personal effects. The cleartext is not known. Can you solve it?
Readers of this blog might know that the /r/Codes group on Reddit is an interesting source for cipher mysteries. Many an encrypted note I have blogged about stems from this group. For this reason, I check /r/Codes occasionally looking for topics I can write about.
During my last check, which took place about 30 minutes ago, I discovered a new post that introduces an unsolved cryptogram. The author of this post is a user who calls himself RetroSA. Here’s the scan he published:
According to RetroSA, this is a note he found in a family member’s personal effects. No additional information is given.
Here’s a transcription of the cryptogram (as provided by a Reddit user named NickSB2013):
ABCDE ABFGH ABIJKLMNO OPBD
OPNQAQRS ATRDH NURDFV OSGA OQCEWKF T UFKOV PGA
DRQAPF OBRSADF EQWXF
A few more Reddit users have commented on this mystery, but the solution is still unknown.
My guess is that this ciphertext has been encryption with a MASC, i.e., a one-to-one letter substitution. If the cleartext language is English, the single letter in the third line (trranscribed as T) probably stands for A or I, the only common one-letter words in the English language. The first letter of the last line might be a word of its own, too (though NickSB2013 has not transcribed it this way). If so, there are two letters we can guess. However, as we don’t know much about the background of this note, other cleartext languages are possible, as well.
Can a reader solve this cryptogram?
Further reading: A famous unsolved crypto mystery: the D’Agapeyeff cryptogram