Useful websites for puzzle solving
This is just a collection of links to websites that I've found to be useful in solving various puzzle based geocaches. It's not intended to be a puzzle solving guide, but I have included some links to guides where appropriate. It's also a somewhat selective collection, as it concentrates on less common and more powerful tools.
WARNING: I have no control over the pages that are linked to from this site. I have tried most of them myself without any problems, but over time, things change. So please exercise caution when visiting websites, and particularly when downloading files. Use an antivirus application on your computer. If you do find a malicious site or file, please let me know and I'll remove the link.
Puzzle Solving Guides
There are plenty of websites which offer guidance on solving puzzles. I'll add some of the more interesting ones here as I come across them.
Purple Hell - The Riddle Tools section of this site was a massive resource of information useful in solving all kinds of puzzles. Unfortunately they seem to have lost their domain registration, and it's now occupied by a domain squatter. The good news is that the site is still mostly available via the Internet Archive's Wayback Machine (just follow the links!).
Parmstro's Geocaching Puzzle Page has general guidance on puzzle solving, links to puzzle solving resources, and much more.
Red Luth Riddle Tools - Chock full of puzzle solving goodness.
Rick Richardson's Linux tools for geocaching - Linux based geocaching and puzzle tools
See the separate page on ciphers.
Number Coding Systems
See the separate page on number coding systems.
Different writing systems can also be considered codes, as they substitute new symbols for individual English letters.
Omniglot is a massive resource for real and artificial written languages - here's a small sample of some that have been used in puzzles:
|Cirth Runes (from The Lord Of The Rings)|
|Uruk Runes (The Lord Of The Rings)|
|Tengwar (The Lord Of The Rings)|
|Klingon (from Star Trek)|
|Futurama alien alphabet|
|Visitor script (from the TV series "V")|
One of the more famous codes/substitution ciphers is the "Dancing Men" cipher from the Sherlock Holmes story of the same name. There is a nice tool for encoding and decoding this at Purple Hell.
Maritime Signal Flags
Historically, there have been a number of systems of flags used to communicate visually between ships. There are a number of places that you can find the International Code of Signals in use today, but if you are thrown a more obscure code, then you need to know where to look. Good places to try are quadibloc and the Peabody Essex Museum.
This site has descriptions for a number of 2D barcodes.
For an online decoder, try the ZXing online decoder. It decodes barcode images in most common formats, including UPC-A, UPC-E, EAN-8, EAN-13 , Code 39, Code 93, Code 128, QR Code, ITF, Codabar, RSS-14, Data Matrix, PDF 417 and Aztec.
Projection and Datum Conversion
- Movable Type (only works with coordinates in degrees/minutes/seconds or decimal degree formats, not decimal minutes)
- Gazza's On-line Calculators (some only work in UTM coordinates, not lat/long)
- Ed Williams' Great Circle Calculator (gives answers with more precision than the above)
- Given a point, a bearing and a distance, project a new point: Use the tool at Movable Type
- Given two points, and a bearing from each point, find the point where the lines of bearing intersect: Use the tool at Movable Type or Gazza's Great Circle Calculator
- Given three points, and a distance from each, find the point by trilateration: I don't know of any online tools for this, so I use OziExplorer. Enter each point as a waypoint, and in the edit dialog, set a proximity circle with radius equal to the distance from that point. Then look for where the circles intersect.
General manipulation of large numbers, or high precision? Try Wolfram Alpha.
For images, I find the GIMP and Irfanview (and it's plugins) to be invaluable. If you don't want to install applications on your PC, there are online image editors that will do some of what you need. For example pixlr let's you determine RGB values for colours, but doesn't import animated GIFs properly. To check for info hidden in image metadata (such as EXIF and IPTC fields), you really can't go past Jeffrey's Exif Viewer.
Okay, this is a variation on image analysis, but there are a number of tools available for embedding data into images. There is a large list of Steganographic software at JJTC.
WARNING: I've had a report from one user of malware associated with Stegdetect, but have been unable to confirm this, so I've left the link active. Before downloading or running any of these files, make sure that you have appropriate antivirus protection in place. If you have any doubt about a link or file, do not download it!
Stenagography detection tools:
- StegDetect - Can detect data embedded using jsteg, jphide, invisible secrets, outguess, F5, appendX and camouflage. Please read the warning above!
- Hiding information in the order of a list
There's an excellent Java applet sonogram viewer for analysing sound files, though it doesn't accept MP3 format.
Here are a few other websites that are generally interesting.
Cross+A is a tool that lets you create and solve a number of grid and word based puzzles. I've not tried the tool, but this page has a good description of a number of grid puzzles, including those invented by Nikoli and others.
Sites No Longer Useful
The pages at http://homepages.cwi.nl/~dik have disappeared, which is a shame as they were a great reference for punched cards, morse and braille variants, and maritime flags.