My guess is that they can be the same ----- it is just unlikely because there are over 2000 words in the list-----it depends on the algo. selection mechanism.
Posted Oct 19, 2018, 5:46 PM UTC
They can all be the same, and in fact:
all all all all all all all all all all all all
is a valid seed phrase (not that you should ever use it for anything other than test transactions).
I had two consecutive words the same, which made me paranoid at first. But I've tested the seed a few times and it's all good. So yes.
Wow------the odds!-----Thanks for the info.
If there were precisely 2000 words, then the odds of any two words being the same are 1/2000, or .05%. If you have a 24 word seed, then that drops the rarity to .05%^23, or 1.14%, so just over 1 in 100 people will have a consecutively repeated word.
they could all be the same.
24 repeats of these words work: bacon, flag, gas, great, slice, solution, summer, they, trade, trap, zebra
"Alright punk, now give us the keys to your wealth."
"BACON! BACON!"
Yes, there can be duplicates in a valid seed.
The 24 word seed is nothing more than a human-friendly representation of a very large number. And just like regular representations of numbers can have repetitions (the number "747" for example), so can the word-representation of a BIP39 seed.
I had 2 words that were the same on my bread wallet.
yes
given that no one actually answered this perfectly reasonable question, yes, they can.
If you have an 11 digit decimal random number, one of the numbers 0-9 must appear appear twice. Does that make it less secure?
Actually not having repeats would make it less secure. It’s how Enigma was broken. Ill give two examples. Say we have a 10 digit code, and it can start with zero(make the math easier). Then we have about 3.6 million permutations. However if there are repeats allowed we have 10 billion. That is over a 99% reduction in security.
Say we have 100 words. The difference is a lot more subtle. If we have a 24 word key, with no repeats we have about if I did the math right 2.82EE46 permutations. However if we allow repeats it jumps to 10^50. Slightly less than 50 fold, which is childs play in modern security, but the point stands. The difference becomes significant when we do a 100 word key. 10^200 vs 10^158. 10^42 times harder to break.
Real world security is very different tho. I mean heck the enigma was mostly broken because every message ended in “Heil Hitler.”