London: Binance, the world's biggest cryptocurrency exchange, estimates that assets worth $6.3 billion were impacted by a hacking attack against the trading platform.But how was such a theft possible, and what does it reveal about the security of cryptocurrencies? AFP takes a look.Is Binance reliable?Binance, the world's largest platform by digital currency trading volume, claims to have 335 million users.That compares to the reported 741 million cryptocurrency owners worldwide cited by Crypto.com.However, Binance has faced its fair share of scandals. Its former CEO, Changpeng Zhao, was convicted in the United States in 2024 for violating anti-money laundering laws, though he was later pardoned by President Donald Trump.