I need to generate a unique 128 bit number and know this number in my web3.js script.
Previously I tried this (create these numbers in my contract and retrieve them to web3.js). It seems impossible.
Now I consider an alternative solution: I instead generate a random number in web.js code and pass it to the contract to be stored in a map.
So the question: How in web3.js to generate a 128 bit random number with almost 100% probability than no other process using my contract generated the same number?