Topic: re-use of addresses - page 6. (Read 5530 times)
Interesting, reusing address analogous to creating history for credit or consumer worthiness. A mulling point.
legendary
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Core dev leaves me neg feedback #abuse #political
Also note that if you receive multiple transactions at an address, and then only spend some of the outputs, the remaining outputs will be left at an address for which the public key is known. Furthermore, if the wallet you are using does not use an unknown value for generating the signature then the remaining outputs become vulnerable.
I suppose what im still not understanding is this part about the remaining outputs would be left at address where the public key would be known. Why would it be known? This change address for the remaining outputs would be a receive only address.
Ok never mind, I think I get it. You mean the other part of the money NOT in the change address.
Also note that if you receive multiple transactions at an address, and then only spend some of the outputs, the remaining outputs will be left at an address for which the public key is known. Furthermore, if the wallet you are using does not use an unknown value for generating the signature then the remaining outputs become vulnerable.
Wait now I'm confused. Are you talking about output to a change address? I thought the change address would be safe because we are not sending from it.
Outputs that are received at a Bitcoin address are individually spent in their entirety. If you are using a wallet with coin control you have the ability to choose which outputs are spent in a transaction, and can therefore make sure that all outputs received at a particular address are spent together in a single transaction. If you are not using coin control, then it is possible that some outputs will be spent separately from others that were received at the same address.
Bitcoin doesn't distinguish between change addresses and receiving addresses. At the protocol level, it's all the same.
ok, so I understand that you shouldn't re-use an address
GreenAddress just wrote a blog post on address re-use:
- http://blog.greenaddress.it/2014/04/30/reusing-addresses-is-bad-m-kay/
But this view is not universal, apparently:
Quote
Attention #Bitcoin : contrary to what USG moles are peddling, NOT REUSING ADDRESSES IS BAD FOR YOUR PRIVACY. http://log.bitcoin-assets.com/?date=04-05-2014#659425
- http://twitter.com/Mircea_Popescu/status/463072372896333825and then:
- http://log.bitcoin-assets.com/?date=04-05-2014#659487
which I read but still have no idea why Mircea would make that claim.
Anybody?
legendary
Activity: 1302
Merit: 1008
Core dev leaves me neg feedback #abuse #political
Also note that if you receive multiple transactions at an address, and then only spend some of the outputs, the remaining outputs will be left at an address for which the public key is known. Furthermore, if the wallet you are using does not use an unknown value for generating the signature then the remaining outputs become vulnerable.
Wait now I'm confused. Are you talking about output to a change address? I thought the change address would be safe because we are not sending from it.
try to explain it to a legit charity that does not care about privacy at all.
example: donation address to seans outpost
he does not care about privacy AT ALL infact he wants the world to know and use that address for donations, and he 'spends' the inputs manytimes a month. explain the risk and/or chance all their donations can be lost by using the same address.
(without meandering into a privacy concern)
example: donation address to seans outpost
he does not care about privacy AT ALL infact he wants the world to know and use that address for donations, and he 'spends' the inputs manytimes a month. explain the risk and/or chance all their donations can be lost by using the same address.
(without meandering into a privacy concern)
Furthermore, if the wallet you are using does not use an unknown value for generating the signature then the remaining outputs become vulnerable.
So to be safe... when spending... always create a transaction that spends any unused part to one or more of your other Bitcoin addresses (or new addresses) that have never spent anything.
And when receiving funds from someone, always receive them at a newly generated address, if possible.
Using these rules would achieve greater degrees of security and privacy than if you did allow yourself to reuse addresses.
Also note that if you receive multiple transactions at an address, and then only spend some of the outputs, the remaining outputs will be left at an address for which the public key is known. Furthermore, if the wallet you are using does not use an unknown value for generating the signature then the remaining outputs become vulnerable.
Yes. There is a second reason for not reusing addresses, and it is to improve privacy. If you are receiving funds from different sources at the same address you still defeat that element.
It should be pointed out that 128 bit security is still beyond brute force for both current and future classical computing. The main reason for not exposing the PubKey is if to protect it in case the strength of that key is ever reduced in the future. This could be due to quantum computing making it possible to implement Shor's algorithm against the key, or ECDSA being weakened through cryptanalysis. In both instances the effective security of the key will be reduced and known keys could be attacked without warning.
It should be pointed out that 128 bit security is still beyond brute force for both current and future classical computing. The main reason for not exposing the PubKey is if to protect it in case the strength of that key is ever reduced in the future. This could be due to quantum computing making it possible to implement Shor's algorithm against the key, or ECDSA being weakened through cryptanalysis. In both instances the effective security of the key will be reduced and known keys could be attacked without warning.
legendary
Activity: 1302
Merit: 1008
Core dev leaves me neg feedback #abuse #political
ok, so I understand that you shouldn't re-use an address
because then people will see the public key rather than
the hex-encoded hash, and it weakens the security
from 160 bit to 128 bit...
But, can you receive multiple transactions at the same
address (as long as you dont send) with no security
compromise?
because then people will see the public key rather than
the hex-encoded hash, and it weakens the security
from 160 bit to 128 bit...
But, can you receive multiple transactions at the same
address (as long as you dont send) with no security
compromise?
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