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101  Bitcoin / Pools / Re: [185 TH] p2pool: Decentralized, DoS-resistant, Hop-Proof pool on: February 25, 2014, 05:52:01 PM
Edit: Since AFAIK, the getwork protocol does not allow workers to be interrupted with new work, we should be able to estimate the expected stales given a specific block frequency. If we assume a 13s worst case latency, that works out to at most 43% stales with a 30 second target. If we assume a 6.5s average, that works out to 21.7% stale. -- that does seem high.

Edit: Apparently Longpolling works around HTTP limitations by having the miner request new work immediately. The server then does not respond until new work is ready. Testing time.


See this:

https://bitcointalk.org/index.php?topic=18313.msg4556966#msg4556966

I don't know of anyone who has got slush's proxy to work with p2pool, I've tried countless times myself - it just doesn't work, in fact I have a feeling that that's what is now causing my p2pool start up error/warning. Your only choice with a blade is to use +1 at the end of your user name/addy which, tbh, is a bit of a waste..... Wink

OK, I finally got P2Pool running and learned the truth. One thing that confused me is that the +1 option does not appear to be documented anywhere. What it does is tell the blade to report diff-1 shares. Apparently, the blades do not support higher difficulty.

Test results are in: no longpoll support. 21% stale for me, I guess. (confirmed with netstat -- only transient connections show up on port 9332) The reported DOA rate varies between 20-40% for some reason.

PS: Slush's proxy does not work because P2Pool does not appear to support the stratum protocol. I may try a different proxy if I think it will result in less CPU usage (for example, using compiled, rather than interpreted code). Better power savings would result from replacing the CPU though.

Edit: P2Pool does support Stratum. Slush's proxy not working is more complex. P2Pool tries to automatically detect whether the worker is using stratum or not. While at the same time, the slush proxy tries to automatically detect if the pool is using Stratum or not (using the getwork protocol). I tried removing that detection from the slush code, and it still didn't work.
102  Bitcoin / Pools / Re: [185 TH] p2pool: Decentralized, DoS-resistant, Hop-Proof pool on: February 23, 2014, 11:18:59 PM
Hey guys, what bad things come from having a high getwork latency? I'm under the impression that stratum makes getwork irrelevant, but I'm a bit worried that mine is quite high (sometimes a few seconds, you can see it here http://www.blisterpool.com/stats in the graphs bit). Is this a symptom of anything in particular? The cpu doesn't seem to be under any enormous stress, but it does peak every now and then...is this the cause?

Also, I helped a miner get configured to run on my p2pool node, and he has some ASICMiner blades (~10.7GH each). Google search results (most seem to be from a year ago) have all told me that they naturally have high DOA rate with p2pool, without any real way to fix it. Is this still the case? His dead rate is around 40-50%. I also noticed the server was getting absolutely hammered with hash > target spam, and I suggested to the miner to use his bitcoin address+1 for his username. It reduced the server spam drastically (from 100/sec to several/sec), and reduced his DOA a little bit, but it also reduced his mean hashing power by about 10%. Could anyone explain to me what's going on here? I'd like to help him get better results.

Is this miner running a stratum proxy locally? each of the 32 chips seem to mostly ask for work independently.
My blade gets work 150 times per minute, meaning that the latency should be at most 12.8 seconds (150/32*60).

I don't actually have P2Pool working yet, but moved the midstate calculations to my Stratum proxy on the assumption it can calculate mid-state faster than the blade.

Edit: Since AFAIK, the getwork protocol does not allow workers to be interrupted with new work, we should be able to estimate the expected stales given a specific block frequency. If we assume a 13s worst case latency, that works out to at most 43% stales with a 30 second target. If we assume a 6.5s average, that works out to 21.7% stale. -- that does seem high.

Edit: Apparently Longpolling works around HTTP limitations by having the miner request new work immediately. The server then does not respond until new work is ready. Testing time.
103  Bitcoin / Development & Technical Discussion / Re: Don't forget to rotate your logs... on: February 23, 2014, 07:08:04 PM
FreeBSD uses a log rotator called newsyslog.

The following line in /etc/newsyslog.conf appears to do the right thing:
Code:
/home/bitcoin/debug.log bitcoin:bitcoin 644  5     100  *  JR /home/bitcoin/sighup.sh

The fields are separated by white-space. They are: 'logfile_name', 'owner:group', 'mode', 'count' (number of archives to keep), 'size' (in kb), 'when' (chose anytime), 'flags' (J->Bzip2, R-> Treat next field as as shell command to run), 'path_to_pid_cmd_file' (filename containing daemon's PID, must start with /), 'signal_number' (optional, omitted in example).

I first tried appending "killall -HUP bitcoind" directly, but the arguments were interpreted as an invalid signal number. With the size limited to 100 kB, the logs get rotated every hour (because they they grow faster than that).

sighup.sh is just a simple shell-script:
Code:
#!/bin/sh
#Sends bitcoind a Sighup.
killall -HUP bitcoind


I was not able to find any 'copytruncate', setting, but it appears to do the right thing.
104  Bitcoin / Bitcoin Discussion / Re: Stolen Bitcoin questions on: February 09, 2014, 09:25:22 AM
How are most bitcoins stolen and how can I avoid that fate?

The initial responses seem to be alluding to wallet-stealing malware.

The thing to remember is that proof of ownership with Bitcoin is knowledge of a private key. For large amounts, the private key should not even be stored on an Internet-connected computer.

Because transactions are irreversible, computer security suddenly has money on the line.

I recommend paper wallets. Of course, you have to keep in mind that if anybody is able to read the keys without your knowledge, they would be able to spend the coins at any time.

I also recommend keeping more than one copy in at least 2 geographically separate locations. While this will increase the risk of theft, it will also reduce the chances of loosing your Bitcoin in some disaster that destroys one location.
105  Bitcoin / Bitcoin Discussion / Re: Why not launch a Blockchain iOS app for each territory? on: February 08, 2014, 10:50:46 PM
iOS is garbage. Always has been, always will be.

Apple is good for overpriced garbage.

Open source or gtfo, you chose a proprietary phone, the problem is your poor decision making.

I have never seen a fully open source smartphone. I'd buy one right away but as far as I know they do not exist.
If I am wrong please point me to an fully open source smartphone Smiley

Finding a "fully open source" computer is hard enough to find, never-mind a smartphone.

Here is one example that is never coming back now that Nokia went Windows phone exclusive: Nokia N900. I heard there was some mis-management as well: firmware updates were adding features, not fixing basic bugs.

Wikipedia list of open-source mobile phones

Android is more open than Apple phones. If you buy it from Google, it is not even carrier-locked. That list says it excludes Android due to proprietary drivers. However, it is common for GNU/linux PC users to install proprietary drivers as well.

Recently, the nouveau project benefited from Tegra driver source code written for Android. Things like register names and functions were disclosed. PS: AFAIK, the PowerVR graphics used by the N900 probably also required proprietary drivers.

106  Other / Off-topic / Re: I don't know what else to do. Forgive me for this. Worth a shot. on: February 04, 2014, 04:21:45 AM

Fuck you. These aren't lies. This is all real truth that I took time to fucking type out and put out there. You're an asshole.


The difficulty is that nobody cares. If they tried, they would quickly burn themselves out.

What is the Monkeysphere?

Even if we did have the capacity to care, it would be difficult (but probably not impossible) to vet all of the sob stories. Bitcoin is a game-changer. Suddenly, you can irreversibly transfer value in minutes. People who don't react with a "this is probably a scam" attitude are setting themselves up to lose a lot of money.

I gather that many Bitcoin enthusiasts are not very rich at all. They spend them almost as fast as they acquire them. I myself made low thousands because I was not able to sell as the price climbed 1000% in November (paper wallets FTW).

I can tell you that a few thousand dollars won't last long if you have to pay rent. One rule of thumb I heard is that rent should not exceed about 30% if income. The corollary is that people spend a lot of their income on rent (or transportation).
107  Economy / Speculation / Re: BTC is being manipulated into stability. But why? on: January 26, 2014, 07:01:36 PM
In the past month volume has bee relatively low.

I suspect early adopters are artificially keeping the price below $1000USD/coin.

This will cost them Bitcoin, but may not be a bad thing in the long-run. One of the criticisms of Bitcoin is that the early adopters control too much of the wealth.

By keeping the price stable; they can encourage Bitcoin adoption and spread coins around (reducing coin concentration) at the same time. In FIAT terms, how much they can buy with their Bitcoins may end up being about the same anyway.
108  Bitcoin / Bitcoin Discussion / Re: Bitcoin could be crime-fighter against credit hacks on: January 26, 2014, 06:37:56 PM
Meanwhile on this same page, 2 users are talking about how they were hacked and lost 100ish BTCs between them.  So yeah, there is that.  We have magic internet money that everyone recommends not storing on the internet.

Offline storage is a very good idea for Savings wallets. The time delay saved me from getting scammed out of 1.75BTC (the scamer was promising a high price If I could sell more than I wanted to).

With credit cards, you have relatively low credit and daily transaction limits. with Bitcoin you can send millions of dollars of value around the world in minutes, while paying pennies in fees.

Credit cards have to be reversible because they are vulnerable to the replay attack. Bitcoin has to be irreversible because it is decentralized.
109  Bitcoin / Bitcoin Discussion / Re: 90 BTC stolen! on: January 26, 2014, 05:48:54 PM
for anyone else concerned about losing their money I highly recommend the following free way to secure your wallet.

1) Install True Crypt on your PC/laptop and create an encrypted volume that is only mounted manually.
2) Install Virtual Box.
3) Create A Linux virtual machine inside the encrypted volume ...
4) Install Armoury, Bitcoin Client, Litecoin etc into the linux virtual machine ...
5) Create your encrypted/password protected armory, litecoin and other wallets inside the virtual machine.
6) do not use the virtual machine for anything other than Sending and receiving crypto transactions, do not install anything other than the bare essential tools you need and do not surf the internet with it.

from inside the virtual machine you should also be able to create a paper wallet for cold storage.

This only works if you never use the host (hypervisor) for anything but launching virtual machines.
If the host is compromised: so is the virtual machine. Keeping it encrypted is about the same security as keeping your wallet encrypted. If you never spend funds, an attacker can't either (assuming the passphrase is secure).

How can two wallets be made to transact at the same time with a single transaction?

If all else fails, this can be done manually. Coinjoin transactions take advantage of this.
110  Economy / Service Announcements / Re: Elliptic Vault - Insured Bitcoin Storage on: January 20, 2014, 03:30:17 PM
I guess I have one question: does your service use more than one geographic location?.
111  Bitcoin / Project Development / Re: Proposing Nanocompensated Servers and a New Paradigm of Social Networking on: January 20, 2014, 03:01:39 PM
I think I found a major design flaw in the proposal:
If the sever wants to get paid, the owner of the server must have a private key only they know. However, if the user is expected to sign all transactions with the the same key: they must also know it. The implication is that if the user was to withdraw funds, they don't actually need to ask the server permission. Because you are micro-billing by the table entry, it would cost extra money to delete all of their posts as well. Doing so automatically may upset users who did not do this on purpose. For example, Bitcoind automatically spends from all coins the user has access to. However, to sign messages, the user must have the corresponding private key in their wallet. There is also the issue where the user much unlock their wallet for mundane status updates: mostly defeating encryption.

One conceptual problem with the design is that bitcoin addresses are not intended to be account numbers. Apparently Bitcoind supports "accounts" that do not actually correspond to specific coins at all (it is possible to have a negative Bitcoin account balance). When sending coins to the server, there may be more than one coin sent. Each coin will have its own input and corresponding private key. With the use of coinjoin transactions, these may not even all be controlled by the same entity. Stealth addresses may mitigate some of these concerns.

Quote from: Peter Todd
Using Elliptic curve Diffie-Hellman (ECDH) we can generate a shared
secret that the payee can use to recover their funds. Let the payee have
keypair Q=dG. The payor generates nonce keypair P=eG and uses ECDH to
arrive at shared secret c=H(eQ)=H(dP). This secret could be used to
derive a ECC secret key, and from that a scriptPubKey, however that
would allow both payor and payee the ability to spend the funds. So
instead we use BIP32-style derivation to create Q’=(Q+c)G and associated
scriptPubKey.
- [Bitcoin-development] Stealth Addresses

BTW, that reddit link appears to be circular: linking back to the same post for the "the technical writeup". I also don't understand how the rock paper scissors example can properly work if all of the database entries are public and verifiable. The code does not require both submissions be submitted at the same time. I am not even sure that would be technically possible since relational databases need to serialize updates.

I also feel that "wallet seeds" (essentially a brain wallet) should not be supported. You say yourself that "to handle money, a deep understanding of... the intricacies of using Bitcoin is required." You go on to say the the goal of netvend is to "(provide) every  internet user (with) easy and cheap access to a neutral server that solves many of these problems." Brain wallets are very insecure unless you know what you are doing. People tend to overestimate the entropy of their passphrases. "Wallet seeds" should not be used: even for examples. If people insist on using a "wallet seed", they can go to brainwallet.org and copy the resulting private key from there.
112  Other / Alternate cryptocurrencies / Re: ***** THE ZEROCOIN SOURCE - Truly anonymous coin ***** on: January 16, 2014, 07:16:37 AM
Neither the Forbes nor soundcloud links worked for me. Forbes redirected me to an AD.

Soundlcoud said "Track not available on mobile". I wonder if it assumes no flash==mobile or something.
113  Bitcoin / Bitcoin Discussion / Re: Say bitcoin eventually reached 100k per. How much do you think transaction fees on: January 16, 2014, 06:39:11 AM
Currently the minimum suggested fees are kind of hard-coded. You currently can't sent transactions of less than about 5000 satoshies.

I think I the price really does go up, it will cost about 10µBTC (1000 satoshies) for the average transaction. At $100,000 per coin, that works out to about $1 per transaction. The fees would help pay for expensive network access full nodes need to maintain. Edit: miners get the fees, not normal nodes though.
114  Bitcoin / Bitcoin Discussion / Re: Bitcoin safety deposit box/wallet...Insure your coins on: January 16, 2014, 06:29:50 AM
What kind of rich asshole has millions of dollars worth of bitcoin but can't be bothered to take ONE DAY to learn how to secure them safely and save at least $20,000/year (per million) on fees? This jerk would also have to trust a third and a fourth party (insurer and government) when neither is necessary if you can simply manage to secure or hide A STRING OF CHARACTERS.  It would take at least a day to set up the insurance policy anyway!!

The proposition is not as easy as it sounds. In the article excerpt (no source is given) Bitcoin vault offering insurance is 'world's first' BBC Link.

The article does not say anything about storage in multiple locations.

You want to guard against two competing things:
  • Theft
  • Data loss

I think the current best way to do this is spit the keys with m of n transactions and Pay to Script hash, and store them in 3 geographically separate locations. The actual vaults should be sealed such that tampering can be detected and the keys regenerated if needed (which opens up social engineering attacks).

I am not sure a rich a Bitcoiner can't do better, based on information from the sparse article. Hopefully their insurance company was able to vet their security procedures while keeping the unique properties of Bitcoin in mind.
115  Bitcoin / Technical Support / Re: Hypothetical: So, your cleaning out closet, boot up old PC from 2010 and find... on: January 16, 2014, 06:06:00 AM
I locked myself out of my own wallet. I think I recall choosing the length such that I can likely brute-force in the next 40 years (about 72 bits96 bits of entropy). I have it written down, so actual typos should be testable within a day.

I am thinking eventually wallets should start to integrate a "crack the password" feature. Though that would not work for extremely long/high-quality passphrases.

OP: I recommend backing up your wallet. Would suck if you crack the password, only to learn the drive crapped out.
116  Bitcoin / Bitcoin Discussion / Re: Could bitcoin network cope with massive adoption? on: January 15, 2014, 08:57:22 PM
I believe the question should be if the network can handle the increased load, but if everyone leaves, can the network handle the sudden loss of hashing power.

If that happens
1.wait for price to crash
2. buy cheap miners
3.Huh
4. Profit.
117  Bitcoin / Bitcoin Discussion / Re: We should stop using the term Bitcoin ATM on: January 15, 2014, 05:48:24 PM
Automatic Bitcoin machine

ABM: which sometimes stands for Automatic Banking Machine were I live.
118  Bitcoin / Bitcoin Discussion / Re: Let There Be Dark! Bitcoin Dark Wallet on: January 14, 2014, 09:15:17 PM

It seems a pretty safe method, except the needing to be careful part.
Sort of a manual form of trezor.

trezor  also does key calculations off-machine.

I reasoned that while a separate machine is ideal, malware can still piggy-back on USB keys.
119  Bitcoin / Bitcoin Discussion / Re: Let There Be Dark! Bitcoin Dark Wallet on: January 14, 2014, 09:06:51 PM

Do you mean the private keys are on your machine only at the time of a transaction?

Yes. I have been using Addresses generated off-line with Vanitygen. I only copy the private key immediately before sending the funds. Using this as an outline, but moving the private key step down

I installed multibit for "normal" transactions, but have not been able to actually spend any funds with it yet.

I think technically, all the coins are actually stored in the Block-chain Smiley

PS: I am not necessarily advocating other people adopt my practice. Manual transactions are error-prone and may involve unusually large mining fees if you are not careful.

I hope to upgrade to N-of-M +P2SH transactions for savings, but that is likely off-topic.
120  Bitcoin / Bitcoin Discussion / Re: Bitcoins Y2k moment to remove the Decimal places fast approaching. on: January 14, 2014, 07:24:48 PM
Ok, I didn't put OP on my ignore list because I thought the quantum kitten was cute.

This is a bad topic title. Shifting the decimal place is a solved problem; assuming Satoshi sub-division is not needed: just use mBTC and 5 decimal places.

I agree Doge may be popular because they chose "better" parameters. However, Bitcoin has not yet proven it is scalable enough to actually need any extra precision. It may become a reserve currency: only used for large transactions. The fees may become comparable to wire transfers today.
 
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