Geocaching Mystery Cache Solving Checklist
General
  • Investigate the GC Number. Is it unusual and/or can it be used somehow?
  • What does the difficulty say? Are we over or underthinking the puzzle?
  • Do we know the difficult of the hide itself? Does it change how we perceive the puzzle?
  • Check the attributes. Anything that suggests it is a field puzzle?
  • Are there unexpected attributes?
  • Check the geochecker. What kind of answer do we need.
  • Check the cache-owner name. Has it been modified?
  • Who is the CO? Do they have specific patterns?
  • Is there underwater hidden HTML comments?
  • Is there white text in the HTML?
  • Is there a background image in HTML?
  • Are there waypoints and do they have a description?
  • Are there gallery pictures and do they have a description?
  • Any special about the hint?
  • Do we know how numbers we are looking for?
Research
  • Title?
  • Text and keywords?
  • GC code
  • Sentences
  • Hidden text
  • hint
  • Any references to popular media (books, movies, lyrics, songs)
  • Any abbreviations
  • Any hidden text in first and last letters
  • Any white text?
  • Any hidden hints/clues in text/highlight
  • Anything that we can count that is 10, 13-15 or 26 numbers?
  • Frequency analyses, count all the things
  • Read the cache page again
  • Anything that suggest we need to rearrange or change based on the posted coordinate?
  • Reviewer publish note
Coordinates
  • Are there extra waypoints?
  • Convert all listed coordinates to What3Words
  • Check all coordinates in map view?
  • Check all coordinates in satellite view?
  • Check all coordinates in street view?
  • Check the two mile radius
  • Do the attributes limit the area?
  • Any other caches that limit the search area
  • Does the puzzle limit the 2 mile radius?
  • What is the Bing code of all coordinates?
  • What is the Google+ code of all coordinates?
  • Convert all coordinates with what3words
  • Is it at the posted coordinates?
  • Can we simply switch the coordinates longitude/latitude?
  • Is it at any of the waypoint coordinates?
  • Are there special street or city or building names?
  • Check Ingress Intel and see if there is anything
  • Do the coordinates draw anything on the map?
  • Check the distances between the coordinates
  • Are there antipodes that make sense?
Usual Suspects
  • Keyboard layout? Fingers, rows, qwerty/dvorak
  • Phone digits?
  • Semaphore shapes?
  • Base conversions?
  • Roman numerals?
  • Periodic Table
  • Route tranpositions?
  • Rotation/Caesar ciphers?
  • Anagrams?
  • Scrabble
  • Clock numbers, use as an arrow
  • Darts
Frequently Used Techniques
  • Image and image? Can we overlay them?
  • Text and Text? Do the text refer to each other?
  • Text and Numbers? Can we turn it into a book cipher?
  • Anything that we can count
  • Simple symbol to letter or number substitutions
  • Any logical reordering possible?
  • Any repeating patterns?
  • Look from all angles, upside down, reversed?
  • Are the number of assignments identical to the number of pieces of information. Do they line up/match.
  • Is there a reference table to could be used to index into or used to draw upon based on a larger set of data.
Binary letter/numbers
  • Can it be any length of binary to base-10?
  • baudot or Murray?
  • Bacon cipher?
  • Do the numbers form a visual drawing?
  • Morse code?
  • Braille?
  • Huffman coding
  • Can we convert it to ASCII or EBCDIC
  • Can it be used as a mask or grille cipher?
  • How many items are there of each? any patterns?
  • Can it be an 7/14/15 bit LCD segment?
  • Any type of knitting instructions?
  • Can we convert it to any other base-X that makes sense?
  • Bitwise operations? AND/OR/XOR?
  • Prime Binary (123579..)
  • Sequential Binary (12345..)
  • Fibonacci Binary (12358..)
  • Barcode (narrow/wide)
  • American Morse/Railroad morse
Tools
  • Use Dcode identifier
  • Use Cryptocrack identifier
  • Use Boxentriq identifier
  • Use Cryptool2 identifier
  • Use multisolver.de multi-solver
  • Use CacheSleuth.com multi-solver
  • Freqyency analyses
  • Pattern analyses
  • Use Cryptograph.pdf to find symbols
Text
  • Scan for repeating patterns
  • Use a text analyzer for frequency
  • Could it be a cipher?
  • Are there misspellings?
  • Are double letters used?
  • Count sentences/words/letters
  • Google the text, are there differences?
  • Roman numerals hidden
  • Morse code hidden?
  • Circles in the letters
  • All the first and last letters
  • NATO alphabet
  • hidden numbers in words
  • Reverse/upside down?
  • Expand text 3X=XXX
  • Wordvalue =A=1 B=2 etc
  • ID of a website (youtube, jigidi, etc)
  • Rhyming words?
  • Syllables
  • trevanion (x characters after punctuation)
  • Looks for words within words with meaning
  • Count words of different length
  • Airport or Radio codes
  • Look for missing or extra dots
Numbers
  • Can we convert it to binary and visualize it?
  • Is it a cipher? Try cipher identifiers?
  • Does it represent braille (1-6)?
  • Can we do a base conversion?
  • Do they specify coordinates in pairs in a matrix?
  • Is it related to a phone keypad?
  • Could it be related to the numbers of keyboard/rows of the numbers?
  • Could it be related to the keypad of keyboard/create shapes?
  • Are the numbers an index into something? Book-ciper? No zeroes?
  • Do the numbers specify an order of something? (All numbers appear once)
  • How often does each number appear?
  • Are there any zeros?
  • Any patterns in the numbers?
  • Are there pairs of numbers that we can add/delete/multiply or divide?
  • Can we google the numbers?
  • Bitwise operations possible? ANd/Or/Xor
  • Can we put the numbers upside-down? Do words appear?
  • Expand numbers 111 =31 and vice verse
  • Spell out numbers ONE TWO THREE
  • Have a lot of 1 and 2, but not 9 and 0, most likely letters
  • Math related? Factorize, multiple, roots, etc
  • Is it Decimal remainder, especially when starting with 0 or have 2*6 digits
Dates
  • UNIX dates?
  • Convert the dates to numbers in Excel
  • Julian day system 2 digits for the year * 1000 and the day number in the year
  • Julian computer day numbers
  • Number of the day in the year and use as number
  • Any significance to the dates? Holiday?
  • Caches published on those days?
  • Use numbers as military time
  • Dates on a calendar, morse, segment, binary, pixel
Images
  • Take a look at the EXIF and other image data
  • Is there any low contrast differences in the background (very similar colors)
  • Is there any low contrast differences in the foreground (letters slightly off)
  • Is there an Error Level Analyses/photoshop evidence
  • Are there any gallery images to analyse?
  • Is there a background image to analyse?
  • Are there extra bytes in the file?
  • Is some form of steganography used?
  • Can we use a grill cipher on the image?
  • Count every object in the images
  • Any of the usual suspects represented on the image?
  • is it a magic eye image?
  • is there something very small on the image
  • check the image dimensions
  • check file names and use as text
  • check the file size and use as a number
  • Animated gif
  • View in 3D
  • Use 3D reflections like glass
  • Clickable Image Map
  • Can it be compared to the original image? THings added/missing?
  • submarines
GC Website
  • Are there references to something that could be a geocache ID (e.g. GC99999)
  • Are there references to something that could be a geocache Code (e.g. 12345656)
  • Are there references to something that could be a Log/cache GUID (e.g. 1234-5656-323-32332-323)
  • Are there references to something that could be a images GUID (e.g. 1234-5656-323-32332-323)
  • Any pathtag references
  • Any waymark refernces
  • Any benchmark references?
  • Any references to other geocachers?
  • Any references to other geocaches?
  • Any references to the cache owner statistics 1000th cache found etc
  • Any suspicious bookmark lists
  • Any references to travelbugs?
  • Any more information in old logs/write notes of owner?
  • Check out the FTF log. Is it the first log?
Math
  • Offset in /Find in PI (round, circles)
  • Offset in /FInd in E (wave, natural, perfect)
  • Fibanacci numbers?
  • Prime numbers?
  • Factorize the numbers?
  • Base conversions?
  • Convert to binary? and proceed
  • Do a checksum count, total each number into a single number.
  • Can we add/delete/multiple/divide pairs of numbers?
  • Is it a cryptarithm?
Ciphers
  • Use all identifiers and multi-solvers
  • Substitution
  • Vigenere
  • Transposition
  • Railfence
  • Playfair
  • Bifid
  • Trifid
Music
  • Tone ladder conversion?
  • Note length of each note?
  • Can it be any of the usual suspects? Braille, Morse etc
  • Difference compared to the real music?
  • Sum connected notes
  • Words of the music?
  • Guitar tabs? Fingers needed to play?
  • Chord numbers
  • Solresol
Colors
  • Rainbow references?
  • HTML color codes?
  • Resistor codes?
  • Crayons names or codes
  • ZX-Spectrum color codes
  • PH Values codes
  • Dog racing colors
  • Wall paint numbers and names
  • VIC CIpher
  • Billiards and snooker references
  • Towbar numbers
  • 25 wire color code
  • Birthstones
  • Cuisenaire rod/réglettes
Sound
  • Compare left and right audio channel
  • Listen to the audio
  • Any morse code in it?
  • Spectrograms
  • Reverse audio
  • phone tones