The founder of major Canadian crypto trade QuadrigaCX, Gerald Cotten, may have stored the exchange’s private keys of CA$190 million ($143 million) in cryptocurrencies on paper in a safety deposit box.

As Bloomberg reported on Feb 15, Cotten has once mentioned the possibility of losing passwords needed to access crypto assets on February 2014. “Even the U.S. government, with the largest computer systems in the world, could not retrieve those coins if you’ve lost the private key. It’s impossible to retrieve those”, he stated.

He further explained that the best way to keep private keys is to print them off and store them offline in a safety deposit box. “So that way you can never have your Bitcoin stolen, unless someone breaks into the bank and steals your safety deposit box”, Cotten added.

Cotten explained: “Essentially we don’t need to go back to the bank every time we want to put money into it. We just remember the addresses of them, send money from our Bitcoin app directly to those paper wallets, and keep it safe that way.”

After the sudden unexpected death of the CEO, QuadrigaCX lost access to CA$70 million ($52 million) in cash and CA$190 million ($142 million) in Bitcoin and other cryptocurrencies. As customers panicked and try to withdraw from their funds, Quadriga’s operations have been shuttered.

Confronting indebtedness, the trade has looked for bank assurance in Canadian court, under court-endorsed creditor protection with the assistance of Ernst & Young Inc.