Introduction: How to Make a Cryptex

In this Instructable I'll show how I made my cryptex.

There is already an Instructable on making a cryptex published lately, but I wasn't satisfied by that one. That cryptex was held together on the outside, like this. I prefer my cryptex held together from the inside, like this. That is by the way the 'real' cryptex, like it is used in the film. Those are harder to make.

A cryptex is a kind of lock with a password, that holds a roll of paper. Author Dan Brown said in his "Da Vinci Code", a book from some years ago, that Leonardo da Vinci invented it, to let messengers carry secret papyrus rolls that the messengers themselves may not read; only the sender and the recipient know the password. If the messenger would smash the cryptex to read the message, a vial containing vinegar which was rolled inside of the papyrus roll would also break even earlier than the cryptex itself, the vinegar would spread over the message, disolve the ink, making it unreadable.
The term 'cryptex' is actually made up by Dan Brown. I don't even know for sure that it's true that Da Vinci invented it, he never actually made one, he would have made a blueprint in his diary, but I never found that page of his diary(so I made my own blueprint, see the next step). What I do know, is that the vinegar thing doesn't work. It doesn't disolve the ink so much that it gets unreadable, it becomes only a little more vague. I tested it with Black Indian ink, several kinds of pen inks, marker pens, ecoline, pencils, and some more; it never worked, just like Wikipedia says.
In the Da Vinci Code, the cryptexes were used different than how they were meant by Da Vinci, in the story they use it as a part of a big puzzle, the answer to a riddle is the password of a cryptex, which contains another riddle that leads to another cryptex, etc. To my opinion the use of cryptexes in such a way is a bit ridiculous, the characters in the book could've just put the cryptex in the freezer so that the vinegar gets frozen, then they could saw it open without danger. But they didn't think of that easy solution in the book.

In the comments below, 'cavingboy92' came up with this genious way to make use of the vinegar vial: on the paper around the vial, don't write with ink, but also with vinegar. If you want to read the message, pour a PH indicator on it(like red cabbage juice), and you can see the text. Or you can just hold it under a low heat source like a light bulb, then you can see it too, because the acid will oxidate.
If the vial breaks, the piece of paper gets all drenched in vinegar, so it's absolutely sure that it's unreadable!
Here is the proof that it works, tested by cavingboy92.
You could also just put the same inkin the vial as the ink where you wrote with on the paper, that would also destroy the message.
If you want more ways on how you could use a vial-break-delfdestroy mechanism, read throught the comments below, there are a lot of people giving suggestions for it, and also on improving the cryptex.
Finally, if you disolve a lot of salt in the vinegar, I think you can lower the freezing point of it so much that it can't get frozen in a normal kitchen freezer, then the freeze method also won't work so easily, you would have to find a special freezer in a lab or something.

Step 1: The Blueprint

Here is a blueprint for the cryptex, see the image below. A bigger version is found here. Try to understand it; when you are building this, you should really know what's going on. If you don't understand it, read through all steps before you start to build. I recommend to read through it anyway.

I got a question about the dimensions I used, these are my measurements:
the whole cryptex
length(from point to point): 14.5 cm / 5.7 in
diameter: 4 cm / 1.6 in

tubes(the diameter is including the thickness)
4th tube(largest): diameter 4 cm / 1.6 in, thickness 0.4 cm / 0.15 in PVC
3th tube: diameter 3.2 cm / 1.25 in, thickness 0,4 cm / 0,15 in PVC
2th tube: diameter 2.5 cm / 1 in, thickness 0.13 cm / 0.05 in ALUMINUM
1th tube: diameter 2.2 cm / 0.85 in, thickness 0.2 cm / 0.07 in STEEL

the dials are made from the 4th tube and the 3th tube, on the outer side, to the 4th tube, they are 1.5 cm / 0.6 in wide, the inner part, made from the 3th tube, is a little smaller, just that a nail fits between.

You don't need to use these dimensions, there are just some requirements for the dimensions of the tubes, see that in the text at the next step.

Step 2: Materials and Tools

These are the things I used to make the cryptex. If you don't have some things, there may be another way to do it, just look where I used the material or tool, and look if you can think of a surrogate.

The choice of the four tubes is really important. They have to fit in eachother, with not too much space between them, and also not too little(they still need to be able to move in eachother.) The two outer tubes are an exception to this, they may fit real tight. I have the outer tubes as PVC tubes, I think that's the best choice, and the inner two tubes I have in metal. The second smallest tube doesn't need to be in metal, but the smallest is better in metal, I think. That is because we will hammer 6 nails through it, which need to stay in that place. That's why we solder it from the inside, to that the nails stay in place. you could use a PVC tube for the smallest tube, but then it better have a thick frame, for the nails. These nails are so important because they are the tabs that go through the notches on the rings. They may not break.

Step 3: The Inner Tubes

1: First, if there is rust on your metal tubes, sand it off. They need to be smooth. If there is rust on the inside, like I had, wrap sandpaper around a stave and move it back and forth through the tube. what you can't see on this picture, is that this piece of tube was already sewed off, I took it a little wide because the exact length will be sewed later on.
2: these are the two smallest tubes. The second-but-smallest already has an incision, where nails fit in.
3: Drill holes in the smallest tube, all spaces between them equal, and on a straight line. The space between them will be the length of the rings aswell; 1,5 cm for me.
4: So now the holes and the incision can overlap.
5: Look how long the nails should be. they should go from the smallest rube to the third tube, and not touch the 4th tube. For me that was 0,7cm.
6: Cut them off on the length we just measured.
7: Hold the smallest tube so, that the holes are on bottom. Now get the nails in the holes, from the inside! So the head of the nails should be inside of the tube. This is a nasty job, you can use scissors or something as a help.
8: Lie solderin the bottom of the pipe, so on the nail heads.
9: Now melt the solder. I did it with a flaming solder iron, but it's no problem if you don't have that, because you can also do it in the oven. Perhaps that's even better because the flame made the inside of my tube charcoaly. If you do it in the oven, just place the tube on both sides on something and set the oven above the melting point of solder, I think 200 degrees Celcius will do for most types of solder. Don't forget to brush some sulphur stuff on the nails! The solder should also fill the close the holes with the nails fully.
10: The third tube should also get an incision, make this incision a little wider than the first one, because it will be the inner part of the rings. If this incision is real small, the one trying to open the cryptex needs to align the rings extremely straight, that it might even not open when the correct password is there, because some rings are just a little offset.
11: This is when I cut the nails off, but you probably already did that.

Step 4: The Rings

1: Now saw rings of the 3rd tube, that fit closely in the space between the nails. Round the edges.
2: Saw rings out of the 4th tube, which cover the smaller rings including the nails. So they should cover all.
3: Glue them together with superglue...
4: ...So that you get this, without the paint. I painted it already, indeed not in the color like you saw it in the introduction, that's because later on I got insatisfied with this colour. I made the inside black, so that, if there would be a little gap between the outer rings, you couldn't see that so easy(no reflection)
5: You have some rings now, paint them. And print alphabet strips, with the length of the outline of the rings; for me was the outline 13.0cm. See the next image if you want to use my alphabet strip.
alphabet strip: I based this on the alhpabet strip from the Da Vinci Code movie, it's almost the same. print in so that it fits exactly around the rings. A bigger image of mine is here.
6: Now line the notches in the rings up, like this. Do it as precise as possible.
7: glue the strip on the rings with hobbyglue, with the letters of your password on one line.
8: Add thin varnish to protect the strips and the rings. I used Varathane varnish which is actually designed for wooden floors, but it is paperfriendly and thin.

You can also engrave the pvc rings if you like, you can do it with a Dremel, or you can unroll a paperclip, hold it in a burner till it glows, and write letters in the PVC. You need to frequently hold the paperclip in the fire. There are indications that PVC fumes give a higher risk of getting cancer, so do it in a well ventilated area.
This is a lot more work than glueing a strip on it, but it may look better if you do it well.

Step 5: The Sides

1: Grind one side of the 2nd tube flat.
2: Get two more rings like the other rings, but the inner and outer part need the same width. they don't necessarily need to be the same width as the 'lock' rings. but on of the needs a notch like those rings, and the other not. But it's no problem if that one does have a notch. Mine has, because i made these off the rests of the tubes I used. Glue the parts together, and while still dyring, you can take the one with the notch for the next step.
3: Glue this ring on that tube. Don't worry if it doesn't donnect properly, this is just a temporary solution, later on, we'll connect them with nails. When this and the other ring is drying, we'll do some other things in the next steps.
4: We're going to make these now. Maybe it looks hard to do, but it isn't, I'll learn you a trick with the Dremel.
5: Take some wood that is a bit round and a screw that can be hold by the Dremel.
6: Decapitate the screw. You probably can't do this with your hands, so place the pincer with the screw in the bench vice and start turning it. Wear glasses, the screw will shoot away. It is also better to place something on the screw already, so it's heavier, and will fall down instead of flying away and you losing it.
7: Place it in the Dremel.
8: Put the piece of wood on it in the middle.
9: Hold it on rough sandpaper like this, and let the Dremel do the work for you. You can still move it a bit while it's turning to make the process even faster. Let the Dremel turn so fast that it just not leaves black spots on the wood. WARNING: You really need to wear glasses with this. The Dremel turns fast and shoots off particles from the sandpaper. This could injure your eyes.
10: Pretty smooth.
11: Make the sides a little smooth aswell.
12: Now we have this, sand the bottoms to make them the same height
13: This is the result. Later on, I made these even some flatter, because I found them too high.
14: Take flat wood
15: Measure this radius with a compass(the piece of wood will go over it)
16: Draw two circles with that radius.
17: Saw them out, you only need to do that roughly, because we will repeat the Dremel trick! The place of the screw is easy to find, because the compass left a hole in the middle.
18: The result of Dremeling.
19: Glue them together, a screw will go through them later.
20: I painted it but that wasn't a good idea, so don't do it yet. A lot of paint went off later because I still needed to work with it, so I had to repaint it later. But look at the cylinder with the yellow border, I made that with the Dremel, it fits in the smallest tube. See the next step for why we need it.
21: First drill some holes in the ring we glued on the second tube, and bring nails in them, also with glue.
22: Cut off the nails on both sides after a bit of drying.
23: Sand both sides smooth with the Dremel.
24: Put a screw in the middle through that cylinder, and connect it to the thing on the left.
25: You now have that on the left. Bring the dial rings around the cryptex, and also the inner tube. We need to know it's natural place for the next steps.
26: Put some glue on the beginning of the smallest tube.
27: Put the part we jsut made, in it. Let it dry for a moment and then take the whole inner thing out, by pushing from the other side.
28: Smash nails through it. I first drilled the holes.
29: Cut of the nails and Dremel it smooth. I wrapped fishline around the wooden part, because there was a little crack, and now it can't crack further.
30: We now have this, bring the other ring around the tube.
31: Saw the tube off, Make it so that nails fit in holes through it like the first time, but this time don't cut them off yet!...
32: ...Because they should be smashed through this wooden thing, again a product of the Dremel trick...
33: ...But first connect that thing to that other end.
34: Now the nails are smashed in, and Dremeled smooth.

Step 6: Finishing

Paint and varnish the sides, and you're finished! Also add some traingles, arrows, or something else on the sides to show where the password should be.

Now you can make a riddle that looks old. Stir some coffee powder in water(You can also do it with normal coffee but I think this works even better), and drench a poem/riddle in it. Take a candle and gently burn the edges. scratch off some grey ashy stuff from the edges and your riddle looks old.

Here is an example of a riddle you could use:
He who makes it, sells it.
He who buys it, doesn't use it.
He who uses it, will never know...
see the answer here

I tried to make my riddle a little Da Vinci Code-like, but my rhyming in English is bad I think. The answer to my riddle is 'oyster'.


treymartin82 (author)2016-08-22

I just came across this today but does anyone have a US version of this? I kinda get the jist of how this works, kinda. I'd like to make a small cheap one out of thick cardboard tubes first and then make them from better materials.

BrianF182 (author)treymartin822016-12-03

I have made one from plans from popular woodworking magazine. They were indepth instructions. I think it was from 2007 or so

mrdogboypieface (author)2016-12-01

Just a few questions:
1. What kind of vial do you recommend?
2. Where can I get that vial?
3. What part of the cryptex breaks the vial when forced open?

JStubbs29 (author)2016-11-05

In the movie it said the vinegar dissolves the papayrus, not the ink

KronoNaut (author)2016-05-23

I just realized, you can make the container part as long as you want, the pins only have to be in the key wheel section. Off to search for longer pipes.

Smccln (author)2013-03-07

But, really with trial and error, you could crack the code...

But, i still want one

Ggg101 (author)Smccln2014-12-03

trial and error won't work. This one has over 308,915,776 combinations and only one is correct. There are 26 letters on all 6 dials. It's highly unlikely that trial and error would ever work

BillyP17 (author)Ggg1012016-04-15

Actually you can crack it with trial and error. All you have to do is crack one letter at a time starting from the opposite end that the dial pulls out of and EVENTUALLY you will get it. And if you use actual words like OP did, all you have to do is be good at word puzzles because if you know a few of the final letters you can guess the whole word.

BillyP17 (author)BillyP172016-04-15

Oh wait, i didnt think of what istarian said...

Istarian (author)Ggg1012015-09-01

Trial and error will work just fine, you'll be there a long time though. The biggest dilemma is that a well-built cryptex will require you to discover each digit in the combination before you can test if it's right because no movement is possible until all the pegs are free to move...

CarsonH1 (author)Istarian2015-09-30

If you tried one combination a second for 16 waking hours, with all the possibilities available on this cryptex, it would take you a little over 14.5 years to try them all. So I refute your claim to "trial and error [working] just fine" unless you've really got nothing better to do.

TheGrayAssassin (author)2015-09-18

how about a vial of ink? self explanatory, and it will make a mess, so you will know if someone tried to break it


or some sort of chemical, nonreplicatory and cannot wash off, viewable under a black light, so u can find out who

CigarSmoker2 (author)2015-06-08

this would make an excellent lock for a pocket door. At first I didn't understand how it worked, but I get it now, thank you.

Law_dud (author)2014-12-14

Yes the original cryptex had papyrus . Which was paper of long ago and the vinegar would dissolve the paper . Paper used to be held together . It was tree pulp held together so the vinegar would break the bond . New paper is different but papyrus was a different paper. You can try making your own paper and using a solvent that would be undone by vinegar

Gartholameau (author)Law_dud2015-06-07

Write your message on a glossy paper using watercolour paints or use a nib pen and write with printer ink. Everyone has some old print cartridges that are no longer useful, but still have a good quantity of ink left. Just empty the cartridge into a container and fountain pen away. Any liquid including water should mess up the printing fairly well. I'm thinking a lighter colour ink would be easier to dissolve.

Kraplax (author)2009-07-09

OMG! This is totally awesome! Oh, why did Instructables digest came so late?! This cryptex idea would fit my puzzle-present for my friend's birthday tomorrow :( guess i'll make it anyway and present him the whole puzzle a bit later :/ I still wonder where to find tubes.. though, i guess i'll try in local store for such things.. Thanks for instructable :)

merijnvw (author)Kraplax2009-07-09

Thanks. I was just lucky, three of the tubes were in my dad's shed, and one tube came from an old damaged tent. But if you are going to make it just for a puzzle, I assume your friend keeps sportive and won't try to lock-pick or break your cryptex or something, you could also make it from cradboard tubes that go around posters. Or just paper... I could think of those tubes made from paper, with 10 or more layers of paper in thickness. It wouldn't hold against a thief, but for a puzzle present it would be good!

Kraplax (author)merijnvw2014-11-13

Better late than never ;) Three (or four?) years ago i finally made it from composite water pipes (PVC+Al+PVC ones) and it turned out really great. In case anyone looks for a material that is easy to handle and work with - PVC tubes are great for cryptex!

Kraplax (author)merijnvw2009-07-09

Well, i looked around for other instructables about Cryptexes, but they don't look that cool. I doubt i'll follow your idea to the letter, but i guess most of your instructable would be done. I guess i wouldn't work that hard on side caps. Maybe some strong glue, but no nails, i guess.

petsenek10 (author)2014-06-05

It says that the video is private?

nstimley (author)2014-04-17

I think in the book it said the Cryptex used a special kind of paper so the PAPER itself dissolved. And is there a way to have the inside be hallowed out so you can store bigger objects in it?

apark3838 (author)2013-07-20

Hey, I had a question about doing this without a soldering iron, you say in the instructions you can use an oven what do you mean by "putting something under both sides" specifically. Can you clarify this a bit?

ThaXified (author)2013-03-15


xvf. (author)2013-01-02

Let me enlighten you. The vinegar is not meant to dissolve the ink but the PAPYRUS itself.

merijnvw (author)xvf.2013-01-07

Let me enlighten you. Read the text or comments for chrissake. Papyrus is not dissolved by vinegar

superrust (author)2012-11-29

What did you use to cut the incisions?

altimus32 (author)2012-09-11

this is an awsome instructable especialy for me because i have a lot of nosey family members

thattori (author)2012-09-11

What kind of material do you use?

Marcus Worsley (author)2012-06-25

i have made a version of my own here is a link, please leave your thoughts and how you think i could improve it

nickmccullough (author)2012-06-02

Great build and a great instructable. definitely favoriting and planning on building a couple as gifts in the future

Jo-dan (author)2012-06-02

you should really sell this as a kit

Dusk Shadows (author)2012-06-02

haha u think that can stop me i can brake into a 79 numbered vault in 5 minutes lol lol lol I CAN"T BE STOPPED MUHAHAHA!

canucksgirl (author)2012-01-12

Very cool. Thanks for sharing. :D

maddiemanahan (author)2010-06-04

Where would you recomend buying the four tubes ?

tech dawg (author)maddiemanahan2012-01-08

I have made a lot of different things with tubes and I always go to LOWES.

kooldoode (author)maddiemanahan2010-08-27

i would say home hardware in the plumbing section, or any hardware store,if you cant find any ask a clerk or someone

SimonRawr (author)2011-07-09

Another way you could make the vinegar vial work is is you wrote on something like tissue paper so the vinegar would dissolve it completely. I also like the idea of adding salt to prevent the freeze method. I was wondering if somebody could figure out a way to make a timed cryptex so that if it wasn't opened in time, the message would be destroyed. That would take some work, but would eventually be worth it for secret spy stuff.

94todd (author)SimonRawr2011-11-06

thats actually exactly the point, had merijvnw read a little deeper into Dan Browns book, paper is not the material the note is written on but rather papyrus, which dissolves in vinegar, im not sure if someone else has already commented on this, but if so i just wanted to bring it to greater attention

merijnvw (author)94todd2011-11-07

had 94todd read a little deeper into this instructable, he wouldn't have placed this comment. pfff

afrausto (author)SimonRawr2011-09-29

Old post, I know.. I would look in to something electronic. Small timer (chip might work best), maybe a motor to crack the vial? Not sure how small it could be though. Sounds like a weekend project for me =)

Pickles5000 (author)afrausto2011-11-07

In the book, pulling to hard on the ends of the cryptex actually moves a lever that has a point attached to it that presses down on the vinegar vile. When enough force is used (less force than required to break the cryptex) it cracks the glass vial containing the vinegar. this acion releases the vinegar which dissolves the papyrus.

bowmaster (author)2011-09-04

I plan to use this to make a cryptex flashdrive, encrypt in digitally, then put back-track linux on it for a top-secret hacker drive.

merijnvw (author)bowmaster2011-09-05

XD good luck!

bowmaster (author)merijnvw2011-09-05

Much better then the "Auto-Hacking Wardrives" on Instructables. This one can be used to actually hack, not just copy random files.

laloworld94 (author)2011-08-23

the paints you are using...wich kind is it? i live in mexico and i think here they dont sell teh citadel paints...

merijnvw (author)laloworld942011-08-29

it's paint from the miniature wargame called warhammer, I have the paint even though I don't play the game. It's a nice type of paint I think

ahurd1 (author)2011-08-07

I'm really excited about trying to make a cryptex. I think I understand the steps, but it should be much easier to understand when I have the actual tubes in front of me.

Thank You

yaly (author)2011-07-05

okay cool, now how do you change the password?

Gossey2002 (author)yaly2011-07-12

I have given this thought with several designs, the best way to describe it is to make the lettered part have a piece under neath it that is an internal gear (, with this you can adjust where the keys letters are on each letter ring. While I cannot describe this in great detail I suggest looking up how to change the code of your cryptex (the small ones Google distributed as part of their give away), the descriptions will show you all the internal workings and give the information you need.

Also, what he said " v ".

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