Editing signers number in multisig contract "problem", thread solved

Technical Discussion
#1

HI, i created a multisig account on testnet, added a friend as a co signer, set number of signs required to 2, and sent out an transaction that required friend to approve it. which is exactly what i would expect it to do…

but what i was not expecting is when i edited multisig contract to require only one authorisation it did not require a second signer,. thanks to NEM being fast, all updated in matter of minutes and i could empty the multisig account alone, without co signers…

This IS a problem

@Saul, please take a look

EDIT: I used nanowallet, was working on multisig contract tutorial…

I tried removing his account from new multisig, this time created by him adding me as a co sign, but i could not do that. I required verification this time… BUT while i was writing this, his wallet confirmed the transactions without entering password, or touching the computer for that matters…

so now it came to that he has no control over his multisig, and it isn’t even visible in the tabs between send and recieve

also a big NO, cancel, i do not authorize button would be appreciated. ie: an option to decline instead of ignore :slight_smile:

we are flatmates, so computers are in the same room, on the same router…

#2

This is behavior as designed. Removing a cosigner from a n-of-n multisig account needs n-1 signatures. In case of a 2-of-2 multisig account it means 2-1=1 signature.
The reason is that if you would need n signatures, then an evil cosigner cannot be removed and in case a cosigner dies / disappears, the multisig account is blocked forever.

#3

ok i get the math now, so only way is to trust your cosigner…

what about the rest? un-aprooved transactions? also because it abides by n-1 rule?

so a multisig with atleast 3 people could be considered secure in “democratic” way?

#4

for 2 people you can setup a 3-of-4 multisig account and each side has 2 keys. But then there is that death / disappear risk again…

1 Like
#5

i didn’t really get what you were saying.
Can you write down the exact steps like 1)… 2)…

#6

you mean as in each person has two accounts?

it’s just if someone would get to either wallet from 1-1 multisig contract it would get to multisig also.

#7

sure

  • user 1 creates multisig- adds his and user two account

  • user 2 edits multisig contract

  • updates number of signs n-1 (was 2)

  • User 1 get auth request - ignores

  • Fees apply

  • user 2 edits multisig

  • removes user 1 account from multisig-

  • user 1 gets auth request, ignores

  • Fees apply

  • user 1 is removed from multisig

#8

not sure i understand what you are trying to say.

Normal behavior. The user that gets removed gets notified of every change.
But he cannot prevent from getting removed in your scenario.

1 Like
#9

ok, then it’s allways n-1 rule there right?

I will include that

Thank you for explaining this to me :slight_smile:

#10