Proof of Visit system on Ruuvi and IOTA


I am looking for people interested in joining an open-source project based on Ruuvi and blockchain (likely IOTA) technologies. Please contact me over Slack if you are interested (user: felipe). For the time being I have done a mock up version of this project using a Raspberry Pi and Javascript Bluetooth libraries. I will create a GitHub repo anytime soon and add that example.

Thanks in advance!
Kind regards

Proof of Visit goals and description

The goal is to design and build a system to provide a proof that one or several machines (e.g. a user smartphone) has been physically close to a certification device (e,g. a ruuvi tag), recording the information in a blockchain.

This is a very general concept which could be applied in many domains, some of which are:

  • prove that two or more parties were together when signing a contract,
  • prove that a guardian does a tour of a secured building every night,
  • prove that the person providing medical care to a relative did actually visit him or her every day,
  • create a rewarding mechanism, e.g. in form of local cryptocurrency, for people visiting your tourist destination, be it a town, a tourist office, or a monument,
  • ensure that digital reputation of a place -e.g. a rating on a hotel- is only given by users which have physically being in the place itself in order to avoid fake reviews or comments
    disclaimer: Tourism and Hospitality is our use case, visit for our background

Simple example of how the system would work:
1- the signing device, e.g. a Ruuvi tag, broadcasts a bluetooth signal to show it’s open to a connection
2- the user opens a dedicated app and launches the signing process by clicking on a button (with a nice UI/UX etc)
3a- the Ruuvi gives a random string to the smartphone, and gives some seconds to the smartphone to sign it
3b- the smartphone takes the random string, signs it with its private key, and gives the bundle back to the Ruuvi tag
3c- the Ruuvi adds a timestamp, wraps the whole message with its own signature, and sends it back to the smartphone
3d- the smartphone sends the whole message as a transaction block to IOTA and
3e- the user gets a final confirmation that the Proof of Visit transaction went OK
Step 3 is automated
Disclaimer: I am not a security expert


Great idea!, i want to follow your project, I am a JavaScript developer from argentina

Hey Pablo, thanks for your interest, please join the IOTA slack ( and look for me (@felipe)!

Hi @fs, I’m also interested. How can I get an invitation to IOTA slack? Trying to join via I get “Failed! invite_limit_reached” message.


Hello @laherran,

IOTA Slack has reached so large audience that new members cannot join, IOTA team is aware of the issue and working on it. Please feel free to discuss this project on Ruuvi Slack channel #iota though :innocent: