This is an interview I found online, since so many described Ivanov as a cheater (also FM Lilov in a long video) I believe it is right to give the accused the possibility to reply:

Cheating scandal – Borislav Ivanov speaks out 17.01.2013 – Recently a 25-year-old untitled Bulgarian player scored 6.0/9 points in a strong GM tournament, with a 2697 performance. His opponents complained, he was searched, and no electronic equipment was found. Still, the case put chess on the front pages of the mainstream media, and led to intense discussions on the Internet. Now Ivanov has given the Russian news portal WhyChess an exclusive interview.
Borislav Ivanov: Revelation
Interview by Maria Grigoryan
Exclusive interview with Borislav Ivanov, 25, a low-ranked master from Bulgaria, who won five games, drew two others and lost two at a tournament in Zadar, Croatia. The five victories were against four grandmasters and a strong master, and Ivanov soundly defeated them all. Afterwards, Borislav Ivanov was accused of cheating in the Croatian tournament.
What happened in the Zadar Open 2012?
The Zadar Open is a tournament that I've played every year for some time now. Well this was the first time that I tried the A tournament and i think my performance was fantastic although there was so much speculation afterwards
How did you react to the accusation that you were cheating?
At first I wasn't surprised about the speculations but suddenly they turned very ridiculous. Some people accused me of using technical equipment that only NASA has, I even heard that I had had my own satelite that transmitted moves during the games... this is horrible! I never thought that human imagination can turn so fantastic just because a 2200 Elo player has played some nice games in a tournament
Did the arbiter take your clothes off, or did they just check your pockets?
Well, I know my body is handsome and beautiful, but I didn't find it enough to show them the real sexual affection I have for other people around me, so I just said no, although they checked my pockets very slowly and my jacket and after they found nothing.... well, may be they were a bit disappointed, cause they were 100% sure I was cheating and of course that's a total lie
How did you manage to beat the Croatian grandmasters?
I dont think there was anything special in my games at all. The Croatian GMs made some horrible mistakes during our games. Of course I practiced a lot with the computer, and after beating Rybka and Houdini by 10-0 each, i was absolutelly sure that no-one was gonna stop me winning. After all the arbiters were kind of polite and intelligent, you know, the other players weren't though....
Did the arbiters make some mistakes during the chess tournament?
I don't think they made any mistakes at all – in the last two rounds they stopped my live streaming because of the speculations, but of course that didn't affect my games much. The most disturbing thing happened on my birthday, the 21st of December! I was kind of celebrating and preparing for a night out to reduce the stress and get rid a bit of the long chess tournament, but the arbiters and the GMs made me a special birthday present – a petition that asks the referee to check if I had any technical equipment on me, one of the best presents I have ever had in my life!
Which is your main profession?
I am actually a student in my home town Blagoevgrad, its a nice town in South West Bulgaria.
Do you have some other hobby but chess?
Hanging out with friends of mine, visiting night clubs, meeting beautiful girls and so on. Actually, before the Zadar Scandal I wasn't so popular at all, but now I see that the more time is turning the more my popularity rises, I just want to play my own chess-style and to have fun playing chess it's still a pity that I am famous for these ridiculous accusations.
Since when do you play chess? Who was your first teacher of chess?
Well I have been playing chess for about ten years, but 2012 was the first time I started learning seriously the chess theory and practising with a computer. My first chess teacher is my coach Marin Atanasov. He has helped me a lot in my chess-progress ever since I have been playing chess. My club is on my side in this scandal, of course and I would like to thank all the people who support me and even make me feel better despite the endless rudeness that I am receiving.
Some people say that you are genius, other that you are cheat, what would you say to them?
Genius or a cheat, that sounds interesting...Well, I'm not a genius, nor a cheat, but just a normal boy that wants to have fun playing chess.

Ivanov speaks out! He is not a cheater!

Oh, I'm glad he cleared that up for us 

It's funny that people accuse others without proof.. Yes, I also think he cheated since logically, we base our judgement on past achievements, elo rating, etc. but just saying that he is a cheater wihtout proof doesn't make any sense...

You don't need proof to accuse someone, proof is for punishment.  You only need reasonable suspicion to accuse someone.

@ Moses
Yes, well, I guess without the proverbial smoking gun they can't ban him from tournaments for 10 years... or have they?  I wasn't aware of any punishment.

Anyone who claims this is a liar , plain and simple. Anyone who would tell such a bald faced lie certainly wouldnt have a problem with cheating . 

can someone link the games in this thread?

also, maybe the guy was cheating, maybe he wasn't. i obviously don't know for sure yet, but in any case that interview makes him sound like an ass.

Indeed.

I might believe 10-0 against Houdini if he was running an IBM 486. However, I am pretty sure a 486 wouldn't even be able to run Houdini, so that kind of sinks it for me.

"Of course I practiced a lot with the computer, and after beating Rybka and Houdini by 10-0 each, i was absolutelly sure that no-one was gonna stop me winning."

Ha, Ha, Ha, yeah right! He beat Houdini AND Rybka each 10-1???? Does this sociopath really expect us to believe this line of cr*p? ...He practiced with the computer alright, the only thing he forgot to mention was that you can't "practice" with one during a tournament game. This human piece of garbage is a total liar.

How do we know he was lying?  We do know that he's a master, so that makes the claim more plausible.  We also don't know the setting he put it on. 

It's a blatant lie, because if you don't specify otherwise, it is assumed that you are running the engine at full strength on decent hardware. And the best player in the world would have no chance in hell of scoring 10-0 in that case, so lesser mortals obviously have less of a chance.

Wow, I just watched the 70 minute long video... this guy wasn't even cheating smart, not even trying to hide it at all, and in multiple tournaments.  As a chess player this guy is 100% trash to me.  Only a lifetime ban by FIDE is satisfactory.  Unbelievable.

The interview is either a poor translation or fake.  It sounded so absurd I stopped reading it.

The games are in the links to the videos by the way.  A 2400 rated master goes over multiple games from multiple tournaments with houdini 3.

That just shows you don't know how to play and win against Houdini, I also won 10-0 against Houdini!

(Since I notice you are not a strong player, Houdini was black in case you were asking yourself)

The video gives a brilliant explanation of what happened during that tournament with Ivanov.  It seems the only ones defending him are ignoring the details or use the defense: "Well, he had a .00000000001% chance of doing that without an engine, so it is possible."

Excellent videos, thanks for posting. Bit of an eye opener.

I believe the 2nd video by Lilov is scary, because it poses one question that Ivanov's defenders don't answer.

What if someone is behind Ivanov, and this year they start to run this scam at high level (not as rating, but just escalating), with 20-50 players in different tournaments?

They could offer 50% of the prize, and some tournaments do have good money prizes (but of course it could be used for gambling), and the player will not reveal the scam, because he would be banished.

It is the end of OTB chess.

I have been thinking for some time that this will eventually kill big money tournaments, and with it, big chess. Without big money to attract top players, likely will be a decline of skill. We could very well be seeing the apex of human ability in chess, right now, with Carlsen, and its all downhill from here.

"I did not have cheating relationship with that engine"