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April 16, 2014, 08:44:32 AM *
News: ♦♦ A bug in OpenSSL, used by Bitcoin-Qt/Bitcoin Core, could allow your bitcoins to be stolen. Immediately updating Bitcoin Core to 0.9.1 is required in some cases, especially if you're using 0.9.0. Download. More info.
The same bug also affected the forum. Changing your forum password is recommended.
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101  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.
102  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.
103  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.
104  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?.
105  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
- [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 and copy the resulting private key from there.
106  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.
107  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.
108  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.
109  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.
110  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
4. Profit.
111  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.
112  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.
113  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.
114  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.
115  Bitcoin / Bitcoin Discussion / Re: Let There Be Dark! Bitcoin Dark Wallet on: January 14, 2014, 03:57:25 PM
well, I have been using the sx tools to manually build transactions: without having the coins actually stored on my machine until I move them.

The project seems to be a effort to tie together a bunch of separate tools that together can replace Bitcoind that tries to do everything.
116  Other / Alternate cryptocurrencies / Re: Openex hacked but coins recovered on: January 14, 2014, 03:50:08 PM
What I was really getting at is why not use a framework, it gives a fair amount of security if used correctly.

I honeslty feel like it would dimish the accomplishment. when you write your own stuff, you have a more intimate knowledge of it than you would with a framework.

I face-palmed here. It is "not invented here" syndrome.

The problem is that computers are too complex for any one person to know. That is why abstraction is used.

The difficulty I have with abstraction is that the abstraction layer (there is more than one) is rarely proven correct. This can lead to abstraction leakage. However, to start proving a whole system is correct will take many man-centuries. It is not something you can do on your own.

Myself, I have been delayed months setting up a simple Bitcoin node intended for merged-mining. I may be overly cautious compared to you.
117  Bitcoin / Bitcoin Discussion / Re: Let There Be Dark! Bitcoin Dark Wallet on: January 11, 2014, 04:45:51 PM
Will this implement coinjoin by default for transactions or enable one to participate continuously in the background when running?

Doing Coinjoin transactions in the background sounds like a bad idea to me.

First, it would require a network-connected machine to have access to your private wallet keys.

Second, even if randomized, the "spam" transactions may be distinguishable from real transactions.

The way coinjoin integration should work is: if you don't need to send immediately, the client should look for other coinjoin participants.

118  Economy / Service Discussion / Facebook app now compromises SMS-based 2 factor authentication on: January 11, 2014, 04:34:15 PM
The new facebook App asks for a lot of new permissions. Among them is "Read your text messages (SMS or MMS)".

This breaks the SMS-based 2 factor authentication used by many Bitcoin services. This means that if Facebook somehow gets your login passphrase (you do use a different one for each website, don't you?), they can now steal all of your Bitcoin stored in those services.

119  Bitcoin / Mining / Re: Miners: Time to deprioritise/filter address reuse! on: December 16, 2013, 11:58:36 PM
The structure of HD Wallets is presented here.

If your are storing leafs, they have 512 bits of data. This is about twice as much data as traditional keys.

In the "serialization format" section, it says that the keys are up to 112 Characters in base-58 format, which is longer than traditional addresses, IIRC. However, in theory, you only have to back these up once.

I think a more interesting question is if this can be made to work with Pay to Script Hash and M-of-N Multisignature Transactions.
120  Bitcoin / Development & Technical Discussion / Re: sx command line utilities - Empower The Sysadmin With Bitcoin Tools on: December 16, 2013, 11:32:25 PM
Okay, who added "--enable-testnet" to the libbitcoin-leveldb-git PKGBUILD?  Roll Eyes

Does this imply that there is no way to switch to testnet at run-time?

Sometimes you don't want to risk "real" coins.

Is there a sane way to have both versions installed?
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