Day 3 Puzzle - Solution

Summary

The puzzle consists of a 15-line file rdm.txt containing:

Hint text: 1 cd 2 rl th wrld
Hex string mapping figlet glyph symbols 3-8. 6 lines of encoded ASCII art (each char encodes a figlet glyph)
Empty line
Hint text: nx2nx cn b prtty gd 11-15. UUencoded data (XZ compressed, GPG encrypted)

The task was to decode the figlet art to recover the GPG passphrase, then decrypt the payload.

Solution

1. Decode the figlet art (lines 3-8)

Time: ~30 seconds (initial exploration)
Line 2 gives hex: 2028292C2E2F3C5C5F607C which maps to symbols: space, (, ), comma, dot, /, <, backslash, underscore, backtick, |. These form the glyph set used in the art.
Lines 3-8 use letters a-k to encode each symbol position. Decoding gives 6 rows of symbol art. When permuted to figlet row order [5,3,0,4,1,2], the result is:

       _      ____      __     _  _   
  __ _| | ___|  _ \    / /__ _| || |_ 
 / _` | |/ _ \ |_) |  / / _ \_  ..  _|
| (_| |_|  __/  _ <  / /  __/_      _|
 \__,_(_)\___|_| \_\/_/ \___| |_||_|

2. Identify the figlet text (passphrase)

Time: ~15-20 minutes of automated searching + hints
Initial attempts (brute force permutations, dictionary words, leetspeak variants, smush mode scans, all fonts): no exact match found. This consumed most of the search time (10-15 min).
Key observations from manual inspection: starts with a shape, ! shape, e shape (so “a!e…”), ends with # shape.
With user hints narrowing to: 7 chars total, starts a!eR, ends #. Searched all pairs for positions 4-5 across fonts/modes.
Found the exact 7-char string: a!eR/e# (tested via figlet -f standard 'a!eR/e#' which renders to match the target art).
Passphrase: a!eR/e#

3. Decrypt the payload (lines 11-15)

Time: ~5 seconds
Lines 11-15 are UUencoded. Decoding gives XZ compressed data, which decompresses to a 139-byte GPG AES256 symmetrically encrypted blob (/tmp/opencode/out.raw).
Decrypting with passphrase a!eR/e# yields:

well done p1 complete
instructions for p2 would go here

Key Breakthroughs & Timeline

Time	Event
~0:00	Identified symbol mapping from hex, decoded art rows, found correct row permutation `[5,3,0,4,1,2]`.
~0:01-0:05	Built Python figlet simulator (`figsim.py`) and validated against system `figlet` - confirmed 1:1 match for standard font cases.
~0:05-0:15	Exhaustive searches: all 720 row permutations × dictionary words × case variants; tried kerning, different smush modes, all installed height-6 fonts. No matches found (this was the longest automated phase).
~0:15	User provided hint: “The text represented by the figlet is the GPG passphrase… contains uppercase/lowercase and some ascii symbols”
~0:16	User provided hint: “The figlet starts with”a!e” and ends with “#” the 4th character is “R””
~0:17	User provided hint: “there are 7 characters in the figlet… first 4 are”a!eR” and last is “#”. Find the remaining two characters”
~0:17-0:18	Brute-forced all pairs for middle 2 chars across fonts/modes; found `a!eR/e#` matches when rendered in standard figlet.
~0:18	Decrypted GPG blob with `a!eR/e#` → success. Result: “well done p1 complete / instructions for p2 would go here”

Files

/home/ehdee/dev/puzzle-blog/day3/oneshot/rdm.txt - puzzle input
/tmp/opencode/out.raw - decrypted GPG blob (139 bytes)
/tmp/opencode/figsim.py - validated figlet simulator

Result

Passphrase: a!eR/e#
Decrypted: “well done p1 complete\ninstructions for p2 would go here”

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