Dunamu, the operator of Korea’s largest cryptocurrency exchange Upbit, is putting priority on protecting investors in the fast-growing crypto market by correcting deposit errors and strengthening its security systems.

The blockchain company has recently returned 154 billion won ($130 million) to investors who had mistakenly deposited money into other people’s blockchain wallets.

Since 2017, there have been 32,770 cases of deposit errors and Dunamu has managed to correct 96.6 percent of them.

Unlike deposit errors in banking transactions, which are easier to reverse, it is difficult to find the real owner of the blockchain wallet that accidently received the money.

But Dunamu has worked with teams at other companies to correct the deposit error as well as upgraded its technology to track down the transaction flow.

On Dec. 10, it collaborated with a team from Polygon, a project designed to solve network performance issues in the blockchain like ethereum, and returned 2 billion won back to the investors who used the Polygon MainNet chain.

In order to support investors in more complicated cases that were impossible to solve with the existing technology, the blockchain company has found out a new way to correct their transaction errors. Since the reversal process might take months, Dunamu preemptively gives the investors the amount they accidentally transferred in Bitcoins.

Also, Dunamu has opened a 24-hour call center to protect investors from voice phishing scammers. A person who has received a suspect transfer request or who has already transferred their cryptocurrency can get help from the center.

The call center is using machine learning technology to constantly upgrade its system by learning about different types of crypto fraud and using that information to prevent such criminal acts.

Even before launching the call center, Dunamu returned 1.3 billion won to investors who lost money to voice phishing scams last year. Most recently, it prevented a 20 million-won voice phishing incident and helped the police to arrest the offender.

Among the four largest crypto exchange -- Upbit, Bithumb, Coinone and Korbit -- the blockchain company was the first to acquire the Information Security Management System certificate, a prerequisite for a safe crypto business operation, for Upbit.

Last month, it received four certificates for personal information protection from the International Organization for Standardization.

As a move to further strengthen protection for investors, Dunamu plans to open “Upbit Investor Protection Center” by the end of this year.