See Theory over on my site for the explanation of how the mixnet works.

To use it, you will need:

• A computer which is on and connected to the internet 24/7.
• Linux. If you're not running Linux you can probably modify the python code without too much work. Only the random-number source is Linux-specific.
• A good source of random numbers, such as a hardware random number generator. This is an alpha proof of concept that uses /dev/urandom by default, which is not a good source. To change the source of random numbers, modify the source code from '/dev/urandom' to whatever source device you wish.
• Your computer needs to have a publicly available IP address (you may need to set up port forwarding for TCP port 17928). OK-Mixnet is IPv4 only, sorry.
• To be on the list! Email me (my email is here) to join the network.
• A friend you want to talk to who is also on the mixnet.

To send a message to a friend, put a file with the message in the directory messages-to-send/<friend_name> (the directory is automatically created for you after setting up a connection). Messages to you will appear in messages-received.

To set up a connection with a friend, so you can send each other messages:

1. Both of you should generate 40GB of fresh random numbers. Put them in a file called <your-ID>.half-pad.

dd if=/dev/urandom of=YOUR_ID.half-pad bs=1M count=40000

2. Both of you should write the current UTC date in a second file.

date -u "+%Y-%m-%d" >THEIR_ID.start-date.txt

The file is short and looks like this:

2021-05-13

3. Exchange .half-pad files, so you each have both half-pad. For security, you shouldn't use the internet for this step. In increasing order of paranoia, use LAN, USB, or CD/DVD.
4. Xor the bin files together, and delete the originals. The final file should be called <their-ID>.pad.

xor --same-size YOUR_ID.half-pad THEIR_ID.half-pad >THEIR_ID.pad && shred -zu YOUR_ID.half-pad THEIR_ID.half-pad

5. Put the .pad and .txt files in the 'pads' directory of ok-mixnet. The directory messages-to-send/<friend_name> will be automatically created in about 10 seconds.