About a month ago, Bitcoin Gold was attacked and worth more than 18 million USD tokens were stolen from exchange. This is not an attack through exchange’s security flaw as usual, but a 51% attack to Bitcoin Gold.

After this incident, 51% attack became a hot topic and many blockchains’ developers posted articles and clarified how safety their chain is. However, this 51% attack safety issue was forgotten soon and people start to chasing other news in the blockchain world.

Although many developers said their chain is safe, I want to see the reality through data analysis. I want to know how likely 51% attack will happen on one specific token.

At the beginning, I have no idea what the result would be like, my only drive was to explore the truth. But after I saw the result, I know this is a very important stuff and others should know it and be warned.

That’s why I create www.cryptoattack.io to show everybody my findings and hope you will get some insight through my analysis.

How I analyze:

For 51% attack, I concern about the return ratio, which is attack profit/attack cost. If you can generate 51% hashing power of the entire network, the attack (which is modify your transaction basically) is fairly easy. So if the return ratio is huge, then an 51% attack will highly likely to happen.

Attack cost data is from niceHash. You can rent hashing power from niceHash and if there is more than 51% hashing power available, you will be able to attack in theory. From their order book, I get the cost to rent 51% hashing power from niceHash on one coin.

Attack Profit data is from coinmarketcap. I use 2h’s largest trading volume from one exchange as the profit. In real scenario, attacker may choose to buy all the orders currently in an exchange. I just use 2h volume for simplicity.

Then, combine them together, I get the result follows: