What are the most secure way to store a huge amount of BTC over a long time and its (detailed) risks? A other assumption is that the owner does not have a very technical background, thus it will not be possible to verify the code of a wallet generator.
I am looking for a detailed overview of the risks. Even unlikely thinks like a biased random number generator of java script used by: https://www.bitaddress.org/ Or that the site is hacked and wallet generation script is malicious just when I want to use it. An other example would be, when I use MultiBit and I store the seed in safe-deposit box it might happen that the software is not longer available and it might be difficult to recover the keys from the seed.