jackg, thanks. Yes but from what I could understand, it's more important to have a long password than special characters. It's better to remember a long sentence (a uncommon sentence, just jibberish).
The difficulty will be incremental by every added character, it's easier to remember a long sentence, the password example I gave is a 88 char password. It will take a couple of quadragintillion years to crack.
No, that is incorrect. Long does not necessarily mean secure. Password crackers are not stupid, they aren't going to just brute force your password one character at a time; they are going to use dictionaries, lists of previous passwords, sentences and phrases from common books, etc. Humans are predictable and password crackers use that predictability in order to better crack passwords. While your password is probably secure, it can be cracked much much sooner than the majority of password cracking calculation sites tell you.
Exactly.
Your password has 19 words in it.
If we say there are 19*3=57 different combinations of 19 words that can be used (capitals and full stops included).
And testing up to 20 words sets gives 184756 number of possibliliies (approx).
According to
this there are about 750000 words in the English dictionary.
So that's 57*200000*750000=8.55x10
12 possililities that they need to test.
Running an algorithm like vanitygen on my old computer does about 300 operations per second (on 1GHz). If you get a higher power computer, it'd be not too difficult to get in if there's enough at stake. (To clarify, seed cracking with 13 words wouldn't work this way as it'd require internet connection/rpc responses of scans of the entie blockchain which has a convenient limit to the rate even on fast computers). If someone has access to a petahertz super computer, it'd take 8550 seconds to crack your password - under 3 hours.
It'd be even easier to crack as those two sentences are actual setences and not like SEEDS with random characters.
I'm not sure how AES encryption works but other encryption types would allow you get parts of the password out i you now certain information about it as there are similarities between different private keys.