ianmiers

12 ms·

61.
by ianmiers 9y ago
It not holding all the data though. Anyone with old coins has to hold at most 2kb of data. They do have to occasionally (think every 1 to 5 years) scan all spends from that epoch to update that data or get someone to do that on their behalf
62.
by ianmiers 9y ago
Mimblewimble doesn't provide very strong privacy protections. Indeed, to a first approximation all it hides is transaction value. The aggregatable transactions only provide privacy if you assume they are generated, fully formed from no
63.
by ianmiers 9y ago
Very good summary of the issue. This is actually a solveable problem. You use a tree of spent serial numbers and non-membership proofs. This basically eliminates the over head to the network of managing serial numbers and checking for dou
64.
by ianmiers 9y ago
Don't "trust us" is not the same thing as you don't have trust anyone. Before this, you had to trust Open Whisper Systems was not coerced and that Intel had not been coerced into backdooring their hardware. Now, you need
65.
by ianmiers 9y ago
As a practical note, on that curve, Zcash is about the limit in terms of complexity for what you can do practically with a SNARK. This is why ZCash is switching to a much faster construction and supporting curve which gives it a lot of roo
66.
by ianmiers 9y ago
Common misconception: If you have crossed the boarder, then within 100 miles of it they can search you. Of course, how you prove you didn't cross the boarder is an open question. But you can in fact refuse the search on that claim. I s
67.
by ianmiers 9y ago
Scarier point: USPS probably knows without that. If these letters are sent out in batches and the envelopes/timing/vender is unique, then all it takes is knowing that 1 letter is abut HIV and then you know all of them are without
68.
by ianmiers 9y ago
So there definitely are other attack options that Zcash on its own does not protect against and in some cases cannot. The biggest being timing. Usage patterns fall seem to fall into that. But do you think the fact that 1/5th of transa
69.
by ianmiers 9y ago
I'm not sure I follow on the "your privacy can be defeated by people upstream or downstream of you." In ZCash, your transaction is completly indistinguishable from the other shielded transactions. The only thing the person yo
70.
Cookies and blockchain: Privacy risks of web payments via cryptocurrencies(freedom-to-tinker.com)
4 points by ianmiers 9y ago|0 comments
71.
by ianmiers 9y ago
It doesn't seem like a necessary step really. The hub still needs a network connection to open channels. With that connection it can run some kind of SPV like client. The bandwidth costs of that approach are larger, but still minimal.
72.
by ianmiers 9y ago
In terms of making finance available to the impoverished, this does nothing. It's just marketing. 0) Biggest barrier is probably TX fees which range from cents to $5 per transaction. (see argument down thread for arguments over how muc
73.
by ianmiers 9y ago
Many people did though. See for example "Edith's" point in the linked article "Edith: There’s a difference between “let’s have a discussion” and “let me tell you what’s up, all you wrong people.”" To me, it's r
74.
by ianmiers 9y ago
It's not the quality, it's the intent. He went for an adversarial debate, not a discussion. The memo reads as him knowingly and intentionally starting a fight. My assumption, from reading the memo, was that he was expressing an op
75.
by ianmiers 9y ago
The problem was the existing MPC protocol for generating the paramaters didn't scale that well. 1) It required participants to stay secure during the entire computation. With 6 people we still had problems because it took long enough p
76.
by ianmiers 9y ago
That was the case. If one of the 6 people completed the computation and discarded the results, the paramaters are secure. Ideally it would have been more than 6 people, but that protocol really didn't scale to more than a handful of p
77.
by ianmiers 10y ago
Oh, there is no good solution. You need to do something using ORAM. There some clever tricks you can use that might be efficient (e.g this paper does some very interesting things: https://www.internetsociety.org/doc/obl
78.
by ianmiers 10y ago
Right, some leakage is inherent and what you provide may be good enough or even the best you can reasonably do. However, There's a long history (even in academic crypto) of what seems like insignificant leakage being important. So it&#
79.
by ianmiers 10y ago
I think this is missing the larger problem with the claim. Yes, using the term clashed with academic cryptography to some extent. But the larger issue was even as they intended to use it, it's not a completely accurate description of
80.
by ianmiers 10y ago
That is a one character change. And it is labeled "urgent fix". So it's certainly possible. But that change appears to do exactly what the variable name suggests setting it to zero would to : stop zcoin tx's from being i
81.
by ianmiers 10y ago
I have no idea. If you can find a single character edit in the commit history, I will look at it. But this certainly is a bug. And it would allow you to steal funds.
82.
by ianmiers 10y ago
what went wrong: TLDR probably Ctrl-C,Ctrl-V. (Just to be clear, this is about Zcoin, not Zcash/Zerocash. The two are completely different) The fix is here. https://github.com/zcoinofficial/zcoin/commit/3
83.
by ianmiers 10y ago
zkSNARKS, the underlying tricky bit of crypto that Zerocash uses to make anonymous transactions, existed before Zerocash/Zcash. There is a bunch of work on them that was published in Eurocrypt/Crypto/TCC etc. For example [0]
84.
by ianmiers 10y ago
No. The issue in the article is fixed in 1.0.1 and the fix is not a stop gap. Here's [0] the pull request. And here is the correct github issue[1]. You are linking to a completely unrelated issue. The article is referring to a bug wher
85.
by ianmiers 10y ago
Certainly looks like the same attack. The talk was given at Usenix on Thursday, which I assume is why it's coming back up.
86.
by ianmiers 10y ago
From what I understand, this is exactly what chip and signature solves and adding a PIN does little. The "credit card numbers" a chip produces are one time use, so skimming them is worthless. And if the POS system is really an
87.
by ianmiers 10y ago
The argument isn't about building code (e.g. safety standards) but more so zoning about neighborhood character. The author's point is that the type of higher density housing that actually makes up Somerville could not be built un
88.
by ianmiers 10y ago
Something that didn't report these statistics. An old version of IOS for one. Does android do this type of reporting?
89.
by ianmiers 10y ago
What have they actually designed from scratch? Most of what comes to mind (Facetime, filevault) it is off the shelf stuff/ at least there were well known designs to ape which had been subject to analysis. This, well if they just copied
90.
by ianmiers 10y ago
This is something Apple really needs to release all the details of. Even if they got the crypto exactly right, they could have picked a privacy budget/ security parameters that just leaks everything. And there is every reason to be ske

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