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+--- Thread: [OMC] Omnicoin Back Online (/showthread.php?tid=4683868)
Omnicoin Back Online - Abraham Lincoln - Feb 16, 2015
The OmniCoin dev team is glad to announce that Omnicoin is now back online. The pools, exchanges, payment processors, etc should be coming back online shortly. It is also safe to now make transactions with OMC.
What Happened
An attacker, who's identity is unknown, performed what is known as a 51% double spend attack. This attack allows them to send Omnicoin to another party, and then later reverse the transaction by essentially rewriting the blockchain. This is not a fault in Omnicoin itself, it is a fault in all POW cryptocurrencies (including BitCoin).
The attacker sent approximately 1.2 million OMC to AllCrypt.com over the course of 6 transactions. After the deposits had reached 6 confirmations, he reversed the transactions on the blockchain, essentially giving himself back the OMC, while still keeping his account balance on AllCrypt. Then he proceeded to sell approximately 200,000 OMC, totally around 2 BTC, which he withdrew.
What We Did
We decided that this type of attack would be too hard to of a hit for Omnicoin and it would be worth it to do a rollback. Instead of a typical hard forking rollback requiring a client update, we used the exact same method the attacker used to rewrite the blockchain. We rewrote the blockchain starting 1 block before the attacker first showed his face, essentially removing and trace of the attack and taking all the OMC back.
What This Means
Just like the attackers attack had side effects (stolen OMC), our rollback will have side effects of its own. All transaction that were made after block 146197 (15-02-09 22:05:05 CST) will be invalidated. Some transactions will resend themselves in new blocks, but some wont.
* - Accessory - Feb 16, 2015
Well this is good to hear!
I'm glad it's back up and functioning.
* - Abraham Lincoln - Feb 16, 2015
(Feb 16, 2015 10:08 PM)Yani Wrote: Doesn't this mean the attacker has his 51% OMC again?
No, the blockchain was rolled back. He no longer has any OMC.
* - brian188246 - Feb 16, 2015
Good to see this fixed?
I don't know much about crypto currencies, but can the attacker just regain 51% again? I mean if he had the resources to do it once can't he do it again?
* - Abraham Lincoln - Feb 16, 2015
(Feb 16, 2015 10:11 PM)brian188246 Wrote: Good to see this fixed?
I don't know much about crypto currencies, but can the attacker just regain 51% again? I mean if he had the resources to do it once can't he do it again?
Yes, he could perform the attack again. We are working to make this attack harder for him to complete, though.
And this time we are prepared.
* - VRUMM - Feb 16, 2015
(Feb 16, 2015 10:09 PM)Abraham Lincoln Wrote: No, the blockchain was rolled back. He no longer has any OMC.
So he lost 1M OMC and got only 2 btc out of this whole mess?
* - Abraham Lincoln - Feb 16, 2015
(Feb 16, 2015 10:15 PM)Sh1eld Wrote: So he lost 1M OMC and got only 2 btc out of this whole mess?
Correct, he lost the all the OMC he stole and only got 2 BTC out of it.
* - VRUMM - Feb 16, 2015
(Feb 16, 2015 10:18 PM)Abraham Lincoln Wrote: Correct, he lost the all the OMC he stole and only got 2 BTC out of it.
LMAO congratulate to this dumb mothafcker.
* - brian188246 - Feb 16, 2015
(Feb 16, 2015 10:13 PM)Abraham Lincoln Wrote: Yes, he could perform the attack again. We are working to make this attack harder for him to complete, though.How can you guys be prepared for this?
And this time we are prepared.
(Not trying to come across douchey, I'm actually just curious :p)
* - Abraham Lincoln - Feb 16, 2015
(Feb 16, 2015 10:18 PM)Sh1eld Wrote: LMAO congratulate to this dumb mothafcker.
Yup, he didn't even make a dent. And in the processes he actually helped strengthen Omnicoin and better prepare us for attacks like this.
(Feb 16, 2015 10:19 PM)brian188246 Wrote: How can you guys be prepared for this?
(Not trying to come across douchey, I'm actually just curious :p)
We're going to start running checks on the network that will alert us instantly to any attack like this.
We've also grown in knowledge about this type of attack and how to quickly fix it. We've got all the software already setup now, ready for a future attack.
Think of this like a drill, it simply tests are ability to cope with this attack. Although it wasn't a planned drill, it helped us become more prepared.
* - Justin Timberlake - Feb 16, 2015
Thanks for handling this smoothly. Has Allcrypt decided to resume OMC trades as well?
Edit: nvm I didn't see it in the 1st line lol
* - well then - Feb 16, 2015
HELL YES. ABRAHAM, YOU FREED THE SLAVES ONCE AGAIN!
Gotta make some bank on this OMC boy!
* - Malevolent - Feb 16, 2015
Good to see everything back and in working order.
* - SIM-2015410 - Feb 16, 2015
(Feb 16, 2015 10:20 PM)Abraham Lincoln Wrote: Yup, he didn't even make a dent. And in the processes he actually helped strengthen Omnicoin and better prepare us for attacks like this.
We're going to start running checks on the network that will alert us instantly to any attack like this.
We've also grown in knowledge about this type of attack and how to quickly fix it. We've got all the software already setup now, ready for a future attack.
Think of this like a drill, it simply tests are ability to cope with this attack. Although it wasn't a planned drill, it helped us become more prepared.
Yup, this was actually quite beneficial to us. As stated, Omnicoin is safe to use once again, and if this happens again we are prepared. Hopefully things should resume as normal, including trade, mining and the auction. Big things are happening!
* - VRUMM - Feb 16, 2015
I think just to be safe, people should do max $50 per exchange from now on. Bter was hacked this week. These sites are not the safest.
Also everyone should stop exchanging OMC on HF, since there are two guys who just got scammed in total of 5 BTC ($1100) worth of OMC today by Nickelodeon. This got to be the worst month for OMC.