In the cyber world, there are lots of secrets. And sometimes they follow people to their graves.

Hardware wallets for cryptocurrency are known to be problematic when it comes to passwords. Lose your password and you likely lose your money–unless you can luck out and find an ethical hacker to help you, as Mark Fraulander from Wired once had to do. But what happens when an entire crypto exchange comes down to one person who has total control of the company’s ‘cold storage‘ or offline wallet?

Gerald Cotten, the 30-year-old founder of QuadrigaCX, Canada’s biggest crypto exchange, died unexpectedly in December, taking with him the password to his company’s storage–known only to him. As a result, the exchange is currently at a loss for how to repay nearly $200 million in client holdings, according to Bloomberg.

Cotten was concerned with security. Bloomberg reports, “He took sole responsibility for the handling of funds and coins and the banking and accounting side of the business and, to avoid being hacked, moved the ‘majority’ of digital coins into cold storage.”

With so much at stake, some question whether the autonomous system of cryptocurrencies, which sought to operate without the need for third-party intervention, still makes sense.

As Bloomberg suggests, the incident serves as a reminder of the risks associated with the unregulated world of cryptocurrencies.

Get the full story at Bloomberg.