MONACOIN

DESCRIPTION OF EVENTS

"MonaCoin, or MONA, is a digital currency created in 2013." "MonaCoin is an open source digital currency and a peer-to-peer (p2p) payment network." "It was predominantly used in Japan." "Dubbed by its creators as “the first Japanese cryptocurrency,” the coin has become somewhat of Japan’s national alternative to Bitcoin or Litecoin." "It was launched in 2013 as part of the MonaCoin Project. It is named after "Monā" or "Mona," an Internet meme based on a cat-like figure created using ASCII characters that were popularized on the online community 2channel (or 2chan), which serves as a major information hub for technology enthusiasts. Development of the currency was also announced over 2han."

"Like its predecessors, the coin was created purely to serve as P2P electronic cash, a decentralized digital currency aimed at Japanese citizens. There are a few key differences that set it apart from the coins that came before it, and this guide is dedicated to drawing out these differences. Conceived in December of 2013, Monacoin was officially born on January 1st, 2014 with no premine." "The cryptocurrency was the brainchild of an anonymous “Mr. Watanabe,” who—like Bitcoin’s Satoshi Nakamoto—has never been incontrovertibly identified."

"The algorithm that powers the cryptocurrency is called Lyra2RE(v2), and the currency itself is a fork of Litecoin. New coins are issued as payment for mining activities, which allows the ownership of tokens to be recorded into the MonaCoin blockchain. MonaCoin has an average block creation time of 1.5 minutes, a time that is much faster than Bitcoin's 10-minute block creation time."

"Processing a block of transactions results in an award of MONA, with the amount of coin awarded for mining activities set to halve approximately 1 million blocks (an estimated three years). The total number of coins that will be ultimately made available is 105,120,000, and no coins were “pre-mined” before becoming available to the public. As a result, the initial developers are not expected to make a profit because no mining activities would be conducted in the early stages."

"Between May 13th and 15th, Monacoin, a cryptocurrency developed in Japan, appears to have suffered from a network attack that caused roughly $90,000 in damages." "[T]his is merely another incident that shows that threat actors exist that are both resourced and sophisticated enough to execute this kind of attack." "[M]eanwhile the title says 51% attack, its possible to achieve this attack around 40-45% hashrate as well (however lower the attackers percentage is, lower the chance of succesfully executing the attack)." "The miner, still unknown at this point, had enough computing power to take as much as 57% of the hashrate at one point in order to execute on this attack."

"The reason why this is taking place is due to Monacoin’s mining difficulty re-targeting system. There is a weakness in this system which allows the next network block to be mined very quickly. Additionally, newer blocks can be issued at a rapid pace. While that sounds positive on paper, the reality is very different. No mining entity should effectively control the Monacoin network by any means."

"-one of the mining community witholds the blocks. -due to buggy diff retarget calculation the next block can be mined very easily. -new blocks can be issued rapidly."

"-result 1 = faulty confirmed payments into exchanges (hidden block with a hidden transaction to different address from earlyer and not to exchange + issuing block with payment to exchange and rapidly issued forged blocks relation to this block -> exchange detects proper number of confirmations, then they free up the real block as well, resulting the original forged blocks to be orphanged -> the new chain has no payment to the exchange, but the payment is alreday in the exchange database -> swapping to other coins and withdraw) -result 2 = and stealing the block reward from a lot of blocks"

"The bug is the quite similar as Verge had a month ago. Increasing block age for deposits will not fix it, but increasing the block confirmations actually secures you from the attack aniway. Exchangers and online services should increase it above 100. (There is difference as in Verge the timestamp itself was faked - here a different algorithmic error plays role, which the developers must first find)."

"As of May 19th, Japan time, the attack is no longer occurring, but most exchanges have halted all deposits while they work on fixes to prevent possible future similar attacks. Monacoin balances held in wallets are considered safe." "Western exchages (Livecoin) lost $90k usd due to attack." "[B]ittrex employee contacted me, and told me that they consider delisting the coin if they cant contact twitter.com/tcejorpniocanom - i gave them contacts who might know how to contact the developer, and suggested them to do 300 block confirmations."

"Monacoin dev sent Lae an email, saying that his current advice for exchanges is to increase confirmations to 100 for now, and that he doesn't have a concrete plan moving forward yet." "The bug is the quite similar as Verge had a month ago. Increasing block age for deposits will not fix it, but increasing the block confirmations actually secures you from the attack aniway. Exchangers and online services should increase it above 100. (There is difference as in Verge the timestamp itself was faked - here a different algorithmic error plays role, which the developers must first find)."

The MonaCoin blockchain was used to launch a sophisticated variant of a 51% attack, which was used to double-spend against a number of exchanges, stealing at least $90k in funds. It appears that the blockchain was not rolled back and no funds were returned to the affected platforms.

HOW COULD THIS HAVE BEEN PREVENTED?

51% attacks can be prevented through a mix of increased block confirmation times and setting checkpoints to prevent large-scale reorganizations. This means the exchange will not credit newly deposited funds, and nodes will be prevented from accepting attacking chains.

Check Our Framework For Safe Secure Exchange Platforms

Vertcoin Vtc Is Currently Being 51 Attacked (Nov 10)
MonaCoin Definition (Dec 20)
monacoin (Dec 20)
https://www.coingecko.com/en/coins/monacoin (Dec 20)
MonaCoin - BitcoinWiki (Dec 20)
Monacoin Network Still Suffers From a 51% Attack Used for Selfless Mining (Dec 20)
51% attack on monacoin : monacoin (Dec 20)
Blockchain's Once-Feared 51% Attack Is Now Becoming Regular - CoinDesk (Dec 20)
Cryptocurrency Miners Are Sabotaging Blockchains for Their Personal Gain (Dec 20)
https://www.ccn.com/japanese-cryptocurrency-monacoin-hit-by-selfish-mining-attack/ (Dec 20)
@tcejorpniocanom Twitter (Dec 20)
Monacoin project (Dec 20)
Industry Dive 51 Attacks (Dec 20)

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