📅 Original date posted:2014-07-25
📝 Original message:The problem is if someone moves system time forward between app launches.
The lockout period doesn't have to be all that precise, it just makes you
wait for the next block, then 5, then 25, and so on. Using a well
known time server over https would also be a good option, but the wallet
app already has the chain height anyway.
On Friday, July 25, 2014, Mike Hearn <mike at plan99.net> wrote:
> Given that the speed at which the block chain advances is kind of
> unpredictable, I'd think it might be better to just record the time to disk
> when a PIN attempt is made and if you observe time going backwards, refuse
> to allow more attempts until it's advanced past the previous attempt.
>
>
> On Fri, Jul 25, 2014 at 7:56 AM, Aaron Voisine <voisine at gmail.com
> <javascript:_e(%7B%7D,'cvml','voisine at gmail.com');>> wrote:
>
>> It's based on the block height, not the block's timestamp. If you have
>> access to the device and the phone itself is not pin locked, then you
>> can jailbreak it and get access to the wallet seed that way. A pin
>> locked device however is reasonably secure as the filesystem is
>> hardware aes encrypted to a combination of pin+uuid. This was just an
>> easy way to prevent multiple pin guesses by changing system time in
>> settings, so that isn't the weakest part of the security model.
>>
>> Aaron Voisine
>> breadwallet.com
>>
>>
>> On Thu, Jul 24, 2014 at 8:21 PM, William Yager <will.yager at gmail.com
>> <javascript:_e(%7B%7D,'cvml','will.yager at gmail.com');>> wrote:
>> > On Thu, Jul 24, 2014 at 10:39 PM, Gregory Maxwell <gmaxwell at gmail.com
>> <javascript:_e(%7B%7D,'cvml','gmaxwell at gmail.com');>>
>> > wrote:
>> >>
>> >>
>> >> Is breadwallet tamper resistant & zero on tamper hardware? otherwise
>> >> this sounds like security theater.... I attach a debugger to the
>> >> process (or modify the program) and ignore the block sourced time.
>> >>
>> >
>> > It's an iOS application. I would imagine it is substantially more
>> difficult
>> > to attach to a process (which, at the very least, requires root, and
>> perhaps
>> > other things on iOS) than to convince the device to change its system
>> time.
>> >
>> > That said, the security benefits might not be too substantial.
>> >
>> >
>> ------------------------------------------------------------------------------
>> > Want fast and easy access to all the code in your enterprise? Index and
>> > search up to 200,000 lines of code with a free copy of Black Duck
>> > Code Sight - the same software that powers the world's largest code
>> > search on Ohloh, the Black Duck Open Hub! Try it now.
>> > http://p.sf.net/sfu/bds
>> > _______________________________________________
>> > Bitcoin-development mailing list
>> > Bitcoin-development at lists.sourceforge.net
>> <javascript:_e(%7B%7D,'cvml','Bitcoin-development at lists.sourceforge.net');>
>> > https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>> >
>>
>>
>> ------------------------------------------------------------------------------
>> Want fast and easy access to all the code in your enterprise? Index and
>> search up to 200,000 lines of code with a free copy of Black Duck
>> Code Sight - the same software that powers the world's largest code
>> search on Ohloh, the Black Duck Open Hub! Try it now.
>> http://p.sf.net/sfu/bds
>> _______________________________________________
>> Bitcoin-development mailing list
>> Bitcoin-development at lists.sourceforge.net
>> <javascript:_e(%7B%7D,'cvml','Bitcoin-development at lists.sourceforge.net');>
>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>>
>
>
--
Aaron Voisine
breadwallet.com
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Aaron Voisine [ARCHIVE] /
npub18g…knkzl
2023-06-07 15:24:23
in reply to nevent1q…vdxg
Author Public Key
npub18gjvug29c4yg46lmplq38e75gg6wn5mn8taytckcsr4jt8p74h3s5knkzlPublished at
2023-06-07 15:24:23Event JSON
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"content": "📅 Original date posted:2014-07-25\n📝 Original message:The problem is if someone moves system time forward between app launches.\nThe lockout period doesn't have to be all that precise, it just makes you\nwait for the next block, then 5, then 25, and so on. Using a well\nknown time server over https would also be a good option, but the wallet\napp already has the chain height anyway.\n\nOn Friday, July 25, 2014, Mike Hearn \u003cmike at plan99.net\u003e wrote:\n\n\u003e Given that the speed at which the block chain advances is kind of\n\u003e unpredictable, I'd think it might be better to just record the time to disk\n\u003e when a PIN attempt is made and if you observe time going backwards, refuse\n\u003e to allow more attempts until it's advanced past the previous attempt.\n\u003e\n\u003e\n\u003e On Fri, Jul 25, 2014 at 7:56 AM, Aaron Voisine \u003cvoisine at gmail.com\n\u003e \u003cjavascript:_e(%7B%7D,'cvml','voisine at gmail.com');\u003e\u003e wrote:\n\u003e\n\u003e\u003e It's based on the block height, not the block's timestamp. If you have\n\u003e\u003e access to the device and the phone itself is not pin locked, then you\n\u003e\u003e can jailbreak it and get access to the wallet seed that way. A pin\n\u003e\u003e locked device however is reasonably secure as the filesystem is\n\u003e\u003e hardware aes encrypted to a combination of pin+uuid. This was just an\n\u003e\u003e easy way to prevent multiple pin guesses by changing system time in\n\u003e\u003e settings, so that isn't the weakest part of the security model.\n\u003e\u003e\n\u003e\u003e Aaron Voisine\n\u003e\u003e breadwallet.com\n\u003e\u003e\n\u003e\u003e\n\u003e\u003e On Thu, Jul 24, 2014 at 8:21 PM, William Yager \u003cwill.yager at gmail.com\n\u003e\u003e \u003cjavascript:_e(%7B%7D,'cvml','will.yager at gmail.com');\u003e\u003e wrote:\n\u003e\u003e \u003e On Thu, Jul 24, 2014 at 10:39 PM, Gregory Maxwell \u003cgmaxwell at gmail.com\n\u003e\u003e \u003cjavascript:_e(%7B%7D,'cvml','gmaxwell at gmail.com');\u003e\u003e\n\u003e\u003e \u003e wrote:\n\u003e\u003e \u003e\u003e\n\u003e\u003e \u003e\u003e\n\u003e\u003e \u003e\u003e Is breadwallet tamper resistant \u0026 zero on tamper hardware? otherwise\n\u003e\u003e \u003e\u003e this sounds like security theater.... I attach a debugger to the\n\u003e\u003e \u003e\u003e process (or modify the program) and ignore the block sourced time.\n\u003e\u003e \u003e\u003e\n\u003e\u003e \u003e\n\u003e\u003e \u003e It's an iOS application. I would imagine it is substantially more\n\u003e\u003e difficult\n\u003e\u003e \u003e to attach to a process (which, at the very least, requires root, and\n\u003e\u003e perhaps\n\u003e\u003e \u003e other things on iOS) than to convince the device to change its system\n\u003e\u003e time.\n\u003e\u003e \u003e\n\u003e\u003e \u003e That said, the security benefits might not be too substantial.\n\u003e\u003e \u003e\n\u003e\u003e \u003e\n\u003e\u003e ------------------------------------------------------------------------------\n\u003e\u003e \u003e Want fast and easy access to all the code in your enterprise? Index and\n\u003e\u003e \u003e search up to 200,000 lines of code with a free copy of Black Duck\n\u003e\u003e \u003e Code Sight - the same software that powers the world's largest code\n\u003e\u003e \u003e search on Ohloh, the Black Duck Open Hub! Try it now.\n\u003e\u003e \u003e http://p.sf.net/sfu/bds\n\u003e\u003e \u003e _______________________________________________\n\u003e\u003e \u003e Bitcoin-development mailing list\n\u003e\u003e \u003e Bitcoin-development at lists.sourceforge.net\n\u003e\u003e \u003cjavascript:_e(%7B%7D,'cvml','Bitcoin-development at lists.sourceforge.net');\u003e\n\u003e\u003e \u003e https://lists.sourceforge.net/lists/listinfo/bitcoin-development\n\u003e\u003e \u003e\n\u003e\u003e\n\u003e\u003e\n\u003e\u003e ------------------------------------------------------------------------------\n\u003e\u003e Want fast and easy access to all the code in your enterprise? Index and\n\u003e\u003e search up to 200,000 lines of code with a free copy of Black Duck\n\u003e\u003e Code Sight - the same software that powers the world's largest code\n\u003e\u003e search on Ohloh, the Black Duck Open Hub! Try it now.\n\u003e\u003e http://p.sf.net/sfu/bds\n\u003e\u003e _______________________________________________\n\u003e\u003e Bitcoin-development mailing list\n\u003e\u003e Bitcoin-development at lists.sourceforge.net\n\u003e\u003e \u003cjavascript:_e(%7B%7D,'cvml','Bitcoin-development at lists.sourceforge.net');\u003e\n\u003e\u003e https://lists.sourceforge.net/lists/listinfo/bitcoin-development\n\u003e\u003e\n\u003e\n\u003e\n\n-- \n\nAaron Voisine\nbreadwallet.com\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20140725/bab41a50/attachment.html\u003e",
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