Hello Everyone,
We have finished our investigation of the recent SSD issue and found the exact reasons for this. It was not a fork as SSD dev thought, or as we thought a double spend attack.
C-CEX had many withdraws and deposits showing on the blockchain that prove we were never on the wrong fork occuring between the 10th and the 21st of September and I know many of you were stating this to us as well.
http://www.argakiig.us/blockchain/ssd/After the wallet upgrade that we did on the 20th, resync and rescan did not find any discrepenacies of the wallet balance and actual user's balances.
The reason why people were unable to withdraw coins in the past couple days was actually due to a wallet issue that allowed it to generate pre-existing wallet addresses after we upgraded and recompiled.
Due to this we had 19 duplicate addresses that belonged to 38 accounts which were sharing deposits. When deposits came to these addresses it was being credited to both accounts on our exchange as these accounts had duplicate wallet addresses. This is how people started selling coins that were being credited to their account despite them not actually depositing them. Of course it is human nature to take advanatge of the situation and If I was a normal trader I probably would have sold coins that did not belong to me too so I do not blame those people. I will say it would have been "nice" if someone had alerted us they were receiving SSD that were not theirs but again I understand. This however, led to our wallet getting emptied of SSD.
Wallet returned previously used addresses instead of really generating the new ones, this should be investigated and explained by the developer. We have not encountered this issue in over 300 wallets from the past so this is an isolated problem.
Now this puts all of us in a bit of a bind because this was a wallet issue and nothing more. I do value everyone who uses our exchange though (everyone I've worked with knows this) and In the effort to keep those affected from completely losing coins/btc we are going to give 300 satoshi per coin lost in the form of a BTC credit. I repeat this does not mean C-CEX did anything wrong I simply do not want people upset with nothing to show for. The btc will be distributed over the next 7 days to the accounts affected.
If anyone who did receive coins that were not theirs and wishes to give them back to those affected by this that is up to their good nature at this point. I am truly sorry this issue happened and we have implemented an extra check in our system to safeguard from this type of thing happeneing again.
-Pride of C-CEX
EDIT: We had an independent developer and upcoming PoD verifier look at the code as well just for further verification.
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