Bitcoin Gold (BTG) About to Hard Fork to Prevent Further 51% Attacks

John Medley
  • Bitcoin Gold (BTG) to hard fork at block 536200
  • This follows the 51% attack in May, which resulted in $18 million (388,000 BTG) in stolen funds

On May 16, 2018 Bitcoin Gold was attacked by an anonymous hacker who managed to control more than 50% of the networks hash rate, with the aim of altering transaction records. At the time, a “double spend” attack was initiated as follows: BTG tokens were sent to exchanges, and withdrawals were made to the attacker’s wallets, reversing the initial deposit transactions using altered records on the blockchain.

 As a result, the BTG blockchain was charged twice for the money stolen.  This attack exposed serious security flaws within the network’s security, resulting in $18 million in stolen funds. The attack was officially announced on the May 19, as an official blog post stated:

An unknown party with access to very large amounts of hashpower is trying to use ‘51 percent attacks’ to perform ‘double spend’ attacks to steal money from exchanges. We have been advising all exchanges to increase confirmations and carefully review large deposits. There is no risk to typical users or to existing funds being held.

Bitcoin Gold's team

Since the date of the attack, the price of BTG (in BTC) has fallen 43% (from 0.007104 to 0.004026).


As covered, Bitcoin Gold then planned a network upgrade aimed at improving its to prevent future breaches, which could help ease the strong bearish trend the cryptocurrency has since ben enduring.

New Protocol, New Opportunities

Before releasing its mainnet to the public, the BTG team conducted closed tests and altered its proof-of-work (PoW) protocol from Equihash to Equihash-BTG. The specs of this new PoW protocol were published on June 12, in an official blog post, in which the team emphasized enhanced security compared to the previous protocol:

The new algorithm doesn’t just protect us from ASIC miners — it moves us into a different “pool” of hashpower, which also gives us a measure of safety against the kind of 51% attacks against Exchanges that happened over three or four days this past May.

Bitcoin Gold's team

The main feature Equihash-BTG has, compared to its previous protocol, is that the amount of hashpower is significantly greater, as “it’s currently used interchangeably by multiple coins, and some of those coins produce new coins quite liberally — they generate a lot of miner rewards, which attracts a lot of hashpower.”

 BTG’s version of the protocol, in comparison to regular Equihash, is better because the new algorithm requires a minimum 700MB of memory to run compared to the minimum of 50MB in the previous version.

In addition, the upgrade introduces an improved version of the difficulty adjustment algorithm that controls the cryptocurrency’s mining speed. This allows for smoother adjustments during spikes in BTG’s hashrate. Despite these improvements, BTG’s team acknowledges that these are only temporary solutions against attacks. A better solution is set to come:

While we know that this parameter change is not a permanent fix — this one change won’t stop ASICs forever — we know it will solve the ASIC-resistance problem for now, and gives us time to consider other alternatives for the longer term, if necessary.

Bitcoin Gold's team

It should be noted that this is not a contentious hard fork resulting in two blockchains, but a network upgrade deemed necessary, that can only be achieved through a hard fork. After seeing its reputation get severely damaged, BTG’s credibility depends on the upgrade.

Hacked Exchange Cryptopia Enables Trading in 40 Different Currency Pairs

New Zealand-based digital asset exchange, Cryptopia has reportedly resumed trading on its exchange as it is now allowing 40 different trading pairs. This, after Cryptopia recently experienced from several different security breaches.

Support For Bitcoin, Litecoin, Dogecoin Pairs Added

Cryptopia’s management announced (via Twitter on March 18th) that it is planning to expand its list of coins which will again be supported on its trading platform. As noted on Cryptopia’s official support website, the exchange has enabled several different trading pairs (as of March 19th, 2019) with major cryptocurrencies. These include bitcoin (BTC), litecoin (LTC), and dogecoin (DOGE).

In response to Cryptopia’s announcement, Twitter user @dgb-chilling, a supporter of DigiByte (DGB), a cryptocurrency that uses five different mining algorithms, said that he had emailed the exchange’s support team to inform them regarding the coin’s latest update (version 6.17.2). He added that “an upgrade was recommended but not mandatory.”

Meanwhile, Chuck Norris (@CryptoTweet6) remarked: 

Now this is good news! Let’s hope the rest of the coins will be released for trading swiftly.

Other users also considered it “good news” that the compromised cryptoasset exchange was gradually resuming its operations. However, one social media user asked when Cryptopia would start enabling deposits while another inquired about why his ARK coins were still not recoverable from the trading platform. He claimed that he had deposited 1,000 ARK, currently valued at around $628, (a popular proof-of-stake based coin) on Cryptopia. The user also complained that his coins were missing “missing because [the exchange] did not update the ARK wallet."

Tens Of Millions Of Dollars Stolen In Hack

On February 27th, 2019, Cryptopia’s management announced that it was “assessing the impact incurred as a result of the hack” which led to the theft of tens of millions of dollars in cryptocurrency. Last month, Cryptopia’s support team had also estimated that the total loss incurred due to the security breaches was of around 10% of its total holdings (in the worst-case scenario).

Notably, the exchange’s official Twitter account had been silent for several weeks (since Feburary 14th). However, it released several announcements, starting in late February, in which it revealed that its staff members were working on securing each customer’s account individually. Cryptopia’s management also noted that it was taking the appropriate measures to ensure that its trading platform is secure when it is officially back online.