Digital Home Cache

Welcome to our home cache - a traditional cache with a non-traditional container.

Have you ever wondered whether a muggle-proof cache can be created in a densely populated city? Have you ever wondered whether a cache can be made available in multiple locations and still have the same container with the same logbook and trade items?
Well, wonder no more. Here is our digital home cache:

• It cannot be muggled* because its container is not physically accessible.
• It can be found and logged in multiple locations because its container is accessible via a global distributed computer network (also known as the Internet).

* Hacking and burglary excluded, of course.


The container of this cache is digital. Its logbook is a database of log entries. The trade items are files. Even though the container is virtual, the cache is not - it has a container with a logbook at the specified coordinates. The container cannot hold trackables - but so do micro and nano physical containers.

In order to access the container of this cache you will need a special tool. Well, not so special nowadays - almost every geocacher carries one already, some even use it as their GPS receiver.
The "special" tool required is a device with a wireless (Wi-Fi) adapter and a browser. This includes:

• smartphones
• tablets
• laptops
• even some e-book readers

This cache is also a multi-location one. We decided to put a lid (an access point) for the virtual container in various places we can call our home. These include our own home, the homes of close relatives and friends, vacation villas, etc - everywhere we can go with short or no prior notice. There are two conditions for putting an access point in such a place:

• It must have permanent access to the Internet.
• There must be no other access points for the container in the same settlement.

So far, there are access points in these locations:

• Sofia
• Plovdiv

Check the additional waypoints for the coordinates of each of the access points. The coordinates of this cache are at the location in Plovdiv.

When you reach the coordinates of an access point connect to the following hotspot:

• Wi-Fi network: DHC
• Password: N/A

Then open the following address in your browser:

dhc.voidland.org

in order to sign the logbook and exchange trade items.

You will be asked for your name - just enter what you typically use to sign logbooks. Then you will be able to enter some text for your logbook entry, or trade items: you can take (download) or leave (upload) an item (a file). Each item you leave should be accompanied by a description for the geocachers that will come after you.
If you have no other idea what to leave in the cache, you may upload a selfie taken on the spot. Most smartphones and tablets make this very easy - just attempt to choose a file and you will be presented with an option to take a new picture instead of selecting an already existing file.
As long as you don't close your browser or reopen the initial page you will be able to edit the logbook entry or remove the items you have just left. If you want to log another person with the same device just reopen the initial page.

Please, notice:

• Signing the logbook does not log your visit at opencaching.de - just like with any other regular cache.
• Do not forget to press the "Save" button after entering the log entry text - otherwise your entry will not be written to the logbook and you cannot claim the cache as found.

The DHC hotspots give you full access to the Internet. You can use it for whatever you like - browsing, downloading huge files, chatting, VoIP calls, synchronizing c:geo, even logging this very cache on geocaching.com. You can use it before, after or instead of accessing the container. We have only two requests:

• Don't do anything illegal even if you deem it right. We just want to be sure that when Gestapo inevitably comes knocking on our door it will be on our own merit.
• Don't share the password in public databases for "kind of free" wireless networks. These hotspots are only for geocachers and their accompanying friends.

The container is accessible via the public Internet in a restricted mode. You can see the logbook entries and the trade items and their descriptions. You can neither sign the logbook nor take or leave an item.

If you have any problems with the cache please report them in the usual way - by a "Needs Maintenance" log entry on geocaching.com.

The container and its multiple lids are implemented using the following hardware and software:

• Servers: Asus EEE PC 901 (Sofia) and Linksys WRT160NL (Plovdiv)
• Access points: TP-LINK TL-WA7210N (Sofia) and TP-LINK TL-WA5210G (Plovdiv)
• Storage for the container: about 7 GB
• Operating systems: Debian GNU/Linux and OpenWRT
• Web server: nginx
• Implementation language: PHP
• Database: SQLite
• Synchronization between the multiple locations: OpenVPN and rsync

The DHC hotspots are provided by the access points. They are weather-proof and can be seen from ground zero. The servers host the site, the database and the uploaded files. They synchronize with each other once every minute, if possible.