Quantum Computing on a Commodore 64 in 200 Lines of BASIC
In an age where companies are selling two-qubit quantum computers for a sum of money that would make your wallet recoil in horror, here we are, stepping off ...
Dices provably fair - Nonce overflow vulnerability
Most of bitcoin dice software use a system to prove the fair play of the server for each bet. Most of them implement this mechanism using two seed (server seed and client seed) combined with a session nonce in the aim to provide a fair random number for each bet and usually this nonce is initialized to 0 after each seed change.
But, what if this nonce is stored in an unsigned integer variable (32bit in 32bit systems, 2³² values)? Theorically after 2³²-1 bets, the nonce goes in overflow and return to 0.
Saving each bet roll for every play in the first 2³²-1 window, will provide a map function:
f: n → roll . (n < 2³²)
that could be used to declare a function g(m) that predicts every future roll:
g (m) = f (m % 2³²)
A simple fix for this problem is to regenerate the server seed and reset the nonce after 2³² bets.
2023
My Journey at the UnitaryHack Hackathon: A Quantum Computing Adventure
This June I emerged as one of the top participants with 9 bounties collected (alongside another exceptional contributor) in the #UnitaryHack Hackathon, hoste...
Ship detection from Sentinel-2 satellite images
A few days ago I came across a yt video discussing the ESA Copernicus program, a European initiative for monitoring earth via a satellite constellation. This...
2020
OCaml and Quantum Computing
Qiskit is a python SDK developed by IBM and allows everyone to create quantum circuits, simulate them locally and also run the quantum circuit on a real quan...
Yallo, a new Tezos language
As someone noticed from the previous post, last weeks I started to write a new programming language for Tezos smart contracts. This project was initially int...
King of Tezos: a smart-ponzi on Tezos
While writing a new programming language, it is often useful to write some real use-cases to test the syntax, the language expressiveness and the code cleann...
Favorite dev quote
Documentation is like sex: when it is good, it is very, very good; and when it is bad, it is better than nothing
New blog
This is my new blog, based on jekyll. I’ll soon import old posts from my old blog.
2016
Contractvm: decentralized applications on Bitcoin
Contractvm is a general-purpose decentralized framework based on blockchain. The framework allows to implement arbitrary decentralized applications in an eas...
2015
Dices provably fair - Nonce overflow vulnerability
Most of bitcoin dice software use a system to prove the fair play of the server for each bet. Most of them implement this mechanism using two seed (server se...
2014
Apache2: redirect different domains to subfolder
In the aim to merge two of my server on digitalocean, today I tried to write a mod_rewrite rule to redirect a secondary domain to a subfolder. After one hour...
2013
MineML: F# miner
MineML is a multithread CPU based bitcoin miner written in F#. At the moment it’s a slow implementation, but the class structure offers the possibility to im...