Amazing, if any of it were true, Upon reviewing this article, I took to myself to spend 1/2 hour and run some of these things, I have a database of 5 million BTC addresses, and every public-key ever used, both hashed and open, and I ran the addresses though the system, I found less than 1,000 addresses have been used as 'seeds', and I found of that only 'one' had ever had a transaction, ... Not VERY INTERESTING ( So somebody ( most likely the OP, created 1,000 private-keys on BTC using 'address' as the SEED, but never used them, ... so what? ); Sounds like somebody was bored that day, and ran a batch file that terminated at 1024

Then there is the BS about using tx's and merkels for your private-key, or hashing them, these are just random numbers after they're hashed, there was NO 'order' to begin, with hashing high-entropy, is high-entropy, if you want to cultivate private-keys for REAL that have been used ( that's the GOAL right?) Then you need to leverage off the human weakness issue and that is seeds need to have a deterministic nature that came from humans, not random shit.

The OP lists 5 ways to 'hack-btc' I found all to be non-workable, certainly if it be true that a few of these were places as back-doors by a wallet 'engineer' ok, I can dig that, but looking at this stuff from 'hacker' point of view its all a waste of time,

Of the 5,  only the one about seed('cat') times N ( running sha256() n times on the result )  was interesting, the OP makes it sounds like he found many where N > 1, ... but the reality is such that if you take all known seeds, and start N'ing them by N++, you will vanish to zero at 2, ... sure you might be lucky and one time at seed*1975 get one hit, ... but that is just an anomaly

The fact is this kind of stuff in real world would be from 'hand rolled' private addresses and its just not that common, unless the guy is an engineer and hand-rolls from SSL, or that is high-entropy, that works.

Given that using random data from the block-chain for your private-key; hashed or not is a jerks game, and thus by definition a JERK has no BTC, thus its a complete waste of time for a 'professional hacker' to follow any information in this post.

IMHO this article is a sci-fi fairy-tale that can be told to bitcoin wannabe's and their boyfriends.