Reverse Geocache Idea

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caughtatwork
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Reverse Geocache Idea

Post by caughtatwork » 28 January 21 11:24 am

Hi All.

I am currently developing an "online version" of the Reverse Geocache and I would like your input.

https://wiki.geocaching.com.au/wiki/Reverse_cache
A Reverse cache is a type of geocache where a finder is guided to a specified location or target location. i.e. The box will help you to arrive at a specific location. At the location, either a log book is revealed to be signed (for example, a box can be opened) or a logging requirement (such as a description of the location or code) is made known to the finder.
You hide a geocache that is "locked" with something like a combination padlock. The geocache is at the published co-ordinates. You use the "geochecker" to list a 2nd set of co-ordinates (which are hidden) where your "code" to unlock the combination lock will be displayed to the seeker. This could be anywhere in a "reasonable" distance as they will need to come back and rehide the box.

Using a browser on their phone which uses their GPS on the phone they visit a page at GCA and are given a "distance" (but no direction) to the location you need to go to get the "unlock code". e.g. 2,456 metres.
They move a distance away and revisit the page and you get a different distance (but still no direction). e.g. 1,589 metres.
Depending on the accuracy of the GPS they now have two "circles" based on where they were and the distance the geocache was from each of the points. Where the two circles intersect the code will unlock at one of them.
They can move a 3rd time and check again and where all 3 circles intersect should be the location. e.g. 923 metres.
That depends on the GPS accuracy, and will never be perfect so as they approach the location they identify, they can check again and again and once they're within 10m of the location will show them the code to unlock the cache.

They unlock the cache, log it, and replace it back at the original co-ordinates.

You could also hide the box at the 2nd set of co-ordinates and then when the seeker gets within 10m of the location, they are given the final co-ordinates which is where the geocache cache is hidden AND the code to unlock it. This means no returning to the original location to rehide the box.

You could also give a third set of co-ordinates. The first set indicates the "area" (like a mystery cache). The 2nd (hidden) provides the distance to get the unlock code. The 3rd would be the geocache which could be nearby and you can only get those co-ordinates when you get the unlock code.

Seems a little convoluted I know, but this gives a way to hide a reverse geocache with a similar experience to a true reverse geocache in getting to an area "unlocks" the geocache BUT you don't have to make the box with all of the technical wizardry inside it. Just a box with a lock and some co-ordinates to get the code.

To minimise brute force the seeker would only get "10 tries per day". i.e. No just running around playing "hotter or colder". They would need a strategy. The seeker would also be restricted to 1 try every 2-5 minutes. i.e. They need to move and wait before trying again meaning a strategy is required as they hone in and less "hotter or colder" just moving around.

That's the pitch and the reasoning behind the details.

I would like input as to whether you think this works, whether this "trivialises" reverse geocaches and whether the restrictions are too tight or loose as well as the ideas on how to hide the cache and get the code without being too painful to have to return the geocache too far away.

I can't guarantee all or any of the suggestions are adopted but a conversation means we can, as a group, help to refine how we can try to increase the numbers of these geocaches.

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Now_To_Morrow
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Re: Reverse Geocache Idea

Post by Now_To_Morrow » 28 January 21 6:20 pm

I like it. The only problem I have with what you've written here is the paragraph, "To minimise brute force...". I imagine a lot of geocachers would resort to brute force if they have to spend too much time 'finding' one geocache that is already in their hands. For this reason I'd prefer your idea of the lock code location being found first and then leading to the actual geocache in the final location, not carrying the cache to the code and back.

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Richary
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Re: Reverse Geocache Idea

Post by Richary » 28 January 21 7:48 pm

You could also give a third set of co-ordinates. The first set indicates the "area" (like a mystery cache). The 2nd (hidden) provides the distance to get the unlock code. The 3rd would be the geocache which could be nearby and you can only get those co-ordinates when you get the unlock code.
I think it would work, though if you took the quoted approach above there actually wouldn't be a need to have a combination lock or similar on the cache, as you wouldn't get the coordinates until you had found the hidden 2nd coordinates.

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WazzaAndWenches
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Re: Reverse Geocache Idea

Post by WazzaAndWenches » 28 January 21 9:07 pm

General concept is good -something new but not too complex.
First option, as No_Tomorrow said, may result in broken boxes.
Second option with the alternative of the third option are better choices.
There are a number of caches on that other server that are based around using alternative technology to find caches. This cache type gives us something to compete with that tech-buzz type caching.

I prefer the third option second option as it can make diff ratings from easy to quite hard (based on distance). Imagine WP1 is in the middle of thick forest/large parkland/urban jungle(a location that's not ideal for hiding a box). Once the searcher nears WP1 they receive some info pointing them to a hidden unlock code that opens a box that's somewhere much more accessible.

Devious thoughts are floating are floating through the slush behind my eyes :-"

This idea is much more appealing than using drone to find a cache.

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Chwiliwr
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Re: Reverse Geocache Idea

Post by Chwiliwr » 28 January 21 9:38 pm

GA8123 was a virtual reverse cache here in WA by fluffyfish. Virtual reverse with a physical final cache once there.

Whilst I did it the way it was supposed to be done a more knowledgeable programmer pointed out that they could 'arm chair' it based on the code that was in place for that particular cache. (I now know that the final coordinates could be obtained with a description by following the source of the webpage to the script that was being used for the calculations.)

Because that cache is now archived I asked the programmer to create one of them on my website but it never got finished due to his workload and lack of enthusiasm for a non paid job.

The concept was to have the browser send the coordinates to my website where it was processed without ever exposing the actual final position to the web user. To try and limit armchair and brute force a limit was made on how many checks in a minute and also it kept the previous value and calculated the time/distance and wouldn't allow the check to complete if the time value was not reasonable for the distance covered supposedly covered.

Not foolproof as multiple browsers/devices allowed multiple checks avoiding these restrictions but GCA could avoid this by having only signed in users do a check.

As far as the concept goes I liked the 'start anywhere and then find a physical cache at the end' that fluffyfish created as his cache.

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Re: Reverse Geocache Idea

Post by caughtatwork » 29 January 21 9:30 am

Chwiliwr wrote:
28 January 21 9:38 pm
GA8123 was a virtual reverse cache here in WA by fluffyfish. Virtual reverse with a physical final cache once there.

Whilst I did it the way it was supposed to be done a more knowledgeable programmer pointed out that they could 'arm chair' it based on the code that was in place for that particular cache. (I now know that the final coordinates could be obtained with a description by following the source of the webpage to the script that was being used for the calculations.)
Without giving anything away, I do have some checks that minimise being able to access the co-ordinates of the code location. It's not perfect but without knowing what I built, I'm not sure I could crack it.

The idea behind the delays between checks and checks per day also help to minimise the number of opportunities that any cracker has to try and brute force it. The number of tries will be based on your logged in account. So I suppose if you have a team of 4 people vying for the code location, they could get up to 40 tries in the same day and collaborate in those terms. To be honest that's not really necessary. As you take a few readings you end up being able to plot the general location and then you head there to narrow it down. 10 tries are probably not needed, but on the other hand newbies who try the cache without really knowing what to do might end up running out of tries.
No_Tomorrow wrote:
28 January 21 6:20 pm
I like it. The only problem I have with what you've written here is the paragraph, "To minimise brute force...". I imagine a lot of geocachers would resort to brute force if they have to spend too much time 'finding' one geocache that is already in their hands. For this reason I'd prefer your idea of the lock code location being found first and then leading to the actual geocache in the final location, not carrying the cache to the code and back.
I accept the "broken box" scenario if have the geocache and then can't easily get the co-ordinates. That's a real problem with any gadget cache as well, so I'll take on board the suggestion to have:
a. The published co-ordinates being the "general location" of the geocache (same as a mystery cache which indicates the general area).
b. A set of co-ordinates that are hidden from view and are used to get to the code location (within 10m).
c. A codeword which is used to "unlock" the geocache.
d. A message to the finder containing instructions (free form which you can use to provide a final set of co-ordinates) to find the geocache.
Richary wrote:
28 January 21 7:48 pm
I think it would work, though if you took the quoted approach above there actually wouldn't be a need to have a combination lock or similar on the cache, as you wouldn't get the coordinates until you had found the hidden 2nd coordinates.
'd like to try and recreate the original concept as much as possible which is to only be able to open the box once you found the location (or in this case the code location and codeword). It also minimises accidental finders as they can't get into the container (although breakage on any locked container is always an issue). But, you are not forced to have a code word. You can just provide the final message to the finder indicating where to find the geocache container.

Challenges I can forsee:
I can see that some people are going to have the published co-ordinates in one state, the code location in another and the final cache in a 3rd. There is nothing I'm going to do to restrict that. It's annoying and I hope that the community can convince hiders to have the components within "reasonable distance" from each other, but in the way of the site, no rules shall be applied to those expectations.

For a true reverse geocache, one that is self contained and doesn't need the website to work out where the geocache is, you simply don't provide the hidden set of code location co-ordinates. You just use the box to determine the location and the box opens by itself.

If we go ahead I'll write up some instructions for the wiki on how to set up the geocache page and we'll be ready to go.

If you would like to "test" this you can do to https://geocaching.com.au/adhoc/reverse.php

You will need to allow our website to access your location, but you should only have to do this once and if you've done it for the home page of the site you probably don't need to do it again.

You will see your own co-ordinates and a "distance" in km (this is only a test, so please ignore the way it's all formatted). There is no timer on the checker yet, so have at it. If you move around you will see the location and the distance change depending on where you are. It only goes to 2 decimals (which is tens of metres) so if you're a long way from the co-ordinates you might not actually see a change in distance, but hopefully you can.

If you move around enough and get enough readings to get the final location, you are asked to let us know how many tries you took. There is a tool in the toolbox that will help to plot some results. https://geocaching.com.au/toolbox/circleintersect/ Note that small variations will give poor results, so try and move a decent distance before retying and plotting.

If you do crack it and get the final co-ordinates, tell me how you did it, then we'll add something to the check that blocks that check.

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Re: Reverse Geocache Idea

Post by mattyrx » 29 January 21 11:39 am

Great idea to have something like this become a feature of the site. I played with GA8123 once and made something similar based of this cache: https://011235813.xyz/revtest. Didn’t get around to tidying it up and hiding anything though. It can be armchaired though the code and has no limitations on the number of times you request a location fix.

I like the idea that the cacher is led to a code/key/instruction on where to find the physical container. I was going to hide something where the box was at the listed cache coordinates. The cacher needed to take it with them on a little walk using the geolocation on their phone to zero in on a physical key so it could be opened – but I’m pretty sure it wouldn’t last too long before it was forced open by someone who couldn’t be bothered looking for the key.

Had a look at the test cache, but as I’m >100km away I can’t see anything update as I move about etc. Though I do think it’s a good idea to have the cache only playable when in a close vicinity (i.e. closer than 100km) though. Keeps the gameplay legit.

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Re: Reverse Geocache Idea

Post by Laighside Legends » 02 February 21 1:58 pm

Sounds similar to the Wherigo reverse caches? Except that is is played through a browser instead of the Wherigo app. On the plus side, this removes a lot of the opportunities to cheat. On the downside, it only works if you have internet access wherever you are.

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