Someone noted that COIN will be insured against theft. Do they already have an insurance arrangement?
It would be interesting to know the premium and the safety procedures that were/will be required by the underwiter.
The precautions that an individual should take to guard against theft of his personal coins seem to be well understood and adequately safe. It is less clear what a company can do to guard against insider theft (technically embezzlement, right?), which could be committed by anyone, including its chief officer(s).
The unique features of bitcoin seem to make the risk of theft from the firm's cold wallets more severe than the risk of theft of ordinary money from its bank accounts. All it takes is to get copies of the private keys. Even Trezor-like hardware wallets could have secret factory-istalled backdoors or be swapped for malicious counterfeits...
There is no perfect solution. Putting money in bank account may protect you from ordinary theft, but it allows the bank and the government to rob you, LEGALLY. Paper wallet is always the best way for cold storage. IMHO it is just too risky to use hardware wallet, basically a black box, to store a huge amount of bitcoin. It is much safer to use an offline generic computer with open source software to handle a long-term saving account. To prevent insider theft, the insurance company may require COIN to use an M-of-N multi-sig address. N chief officers will generate private keys privately and independently. Each chief officer will physically sign a statement like this: I, <name>, am the generator of the private key for <public key>. The private key is stored in the vaults of <bank A> and <bank B>. Except the copies in the said vaults, there is neither physical nor digital copy of the private key. In case a theft occurred without breaking the vaults, these chief officers would have civil and even criminal liability. So the only problem left is the physical security of the vault. The risk is actually much smaller than storing gold in vaults because it is impossible to have M-of-N multi-sig gold. |
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About 100XBT bought in the last 3 trading days
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黄金的标的物是什么？
比特币不是货币也无所谓。只要能有类似黄金的储备价值就行了。
只是储备的话，BTC长远来看价值 还不如美元，就像黄金該說你腦殘還是什麼? 100年前, 1oz黃金只能換19美元; 10年前, 能換400美元; 今天能換1300美元 你是靠说不买黄金的都是脑残来忽悠大妈买黄金的？ 100年前1美元能买多少东西？今天1美元能买多少东西？货币增发和经济增长你不计算？存钱利息你不计算？ 就不考虑价格贬值，$19 * 1.05^100 > $2498 比你的黄金可高出快一倍的价咯。 任何货币之所以有价值，在于投资、交易过程中获得的真实价值体现。跨度100年还只关注纸上数字是不行的。 說你腦殘就是沒有冤枉. 我不是說了嗎? 100年前1美元能買1/19oz = 1.63克 黃金, 今天只能買1/1300oz = 0.024克黃金 货币增发當然不用計算, 因為這正是美元貶值的原因. 你持有一張100年前的1元美鈔, 難道美國政府會因為货币增发, 今天給你換一張100元美鈔嗎? 銀行利息? 這還要你存對了銀行. 隨便搜了一下, 就發現這幾年每年都有雙位甚至三位數字的美國銀行倒閉 http://www.baidu.com/s?wd=%E7%BE%8E%E5%9C%8B%20%E9%8A%80%E8%A1%8C%20%E5%80%92%E9%96%89&rsv_bp=0&tn=baidu&rsv_spt=3&ie=utf-8鼎鼎大名的雷曼兄弟, 你不會沒聽過吧? 如果要逃過銀行倒閉, 你就只有像大媽們把現鈔塞在綿被內. 這麼一來就沒有利息了. 楼上数学及格就开始到处斗嘴。  资本市场不仅仅是存款，还有多样化的投资。你要观测100年就要按长期投资来计算复利。 楼上你存钱的银行倒闭了嘛？有这么大仇恨呀，还是把资产全换成黄金等解套呢 你在搬龍門嗎? 你的原話是: " 只是储备的话，BTC长远来看价值还不如美元，就像黄金". 本來只是美元vs黃金, 怎麼現在扯來什麼"多樣化投資"? 誰都知道有很多投資比黃金要回報好 不過就算是投資, 也要你投對了市場. 100年來說, 投在道指當然比黃金好得多; 但如果你投在中國, 你過了8年中日戰爭, 恐怕也過不了10年文革 |
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黄金的标的物是什么？
比特币不是货币也无所谓。只要能有类似黄金的储备价值就行了。
只是储备的话，BTC长远来看价值 还不如美元，就像黄金該說你腦殘還是什麼? 100年前, 1oz黃金只能換19美元; 10年前, 能換400美元; 今天能換1300美元 你是靠说不买黄金的都是脑残来忽悠大妈买黄金的？ 100年前1美元能买多少东西？今天1美元能买多少东西？货币增发和经济增长你不计算？存钱利息你不计算？ 就不考虑价格贬值，$19 * 1.05^100 > $2498 比你的黄金可高出快一倍的价咯。 任何货币之所以有价值，在于投资、交易过程中获得的真实价值体现。跨度100年还只关注纸上数字是不行的。 說你腦殘就是沒有冤枉. 我不是說了嗎? 100年前1美元能買1/19oz = 1.63克 黃金, 今天只能買1/1300oz = 0.024克黃金 货币增发當然不用計算, 因為這正是美元貶值的原因. 你持有一張100年前的1元美鈔, 難道美國政府會因為货币增发, 今天給你換一張100元美鈔嗎? 銀行利息? 這還要你存對了銀行. 隨便搜了一下, 就發現這幾年每年都有雙位甚至三位數字的美國銀行倒閉 http://www.baidu.com/s?wd=%E7%BE%8E%E5%9C%8B%20%E9%8A%80%E8%A1%8C%20%E5%80%92%E9%96%89&rsv_bp=0&tn=baidu&rsv_spt=3&ie=utf-8鼎鼎大名的雷曼兄弟, 你不會沒聽過吧? 如果要逃過銀行倒閉, 你就只有像大媽們把現鈔塞在綿被內. 這麼一來就沒有利息了. |
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Dell accepting bitcoin could be MUCH bigger than you think http://ww4.sinaimg.cn/bmiddle/6d9e93aajw1eii0tf52tgj20hs0h6ac5.jpgAndy, a Chinese, shared his experience on Weibo (Chinese Twitter). With the 10% discount, he bought an Alienware 14 ( http://www.dell.com/us/p/alienware-14/pd.aspx) for 6442CNY in bitcoin The same item is selling at 11999CNY in China: http://item.jd.com/1107676.html . He saved 46% You may wonder why he couldn't buy it from dell.com directly before. Due to strict foreign exchange control, Chinese people could hardly have a "foreign currency credit card", and usual credit cards could not pay bills in USD or other foreign currency. As Dell now accepts bitcoin, Chinese people could order from dell.com directly, asking them to deliver to the US address of Haitao ( http://www.haitao.com/ ), who will then ship the item to China. This is only the beginning. But normal Joe Blogg's Chinese can't get Bitcoin easily. 46% discount should provide enough incentive for Joe Bloggs to open an account on huobi or okcoin. Despite China has banned bitcoin 10 times, I can tell you that, based on my first hand experience, Chinese people could still deposit fiat to exchanges in less than 30 minutes. That is correct. Care to give out detail on how an average citizen can do fiat deposit? What about withdraw? Exchange has a list of authorized middlemen. Client sends fiat to a middleman with bank transfer, and the middleman will deposit CNY to the client's exchange account. It could be done within 30 minutes Withdraw is same as before. Nothing has changed. Isn't this easy for government and bank to find out? There are millions of bank transaction each day. How do they know the money is not for Magic the Gathering card trading? |
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黄金的标的物是什么？
比特币不是货币也无所谓。只要能有类似黄金的储备价值就行了。
只是储备的话，BTC长远来看价值 还不如美元，就像黄金該說你腦殘還是什麼? 100年前, 1oz黃金只能換19美元; 10年前, 能換400美元; 今天能換1300美元 |
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It would be possible with a hard fork.
blah blah blah
Most everything is possible with a hard fork |
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I mean it's one more step and one more big company going the experimental way of accepting bitcoin. How many companies are just in for the media hype remains to be determined, but it's nevertheless a very important step for the self-fulfilling-prophecy theory that an increased adoption leads to an even higher adoption. I just hope those companies don't just drop bitcoin anytime soon  Have any done so, actually? I couldn't see why they would drop bitcoin, as it costs them nothing to accept bitcoin. |
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...
Exchange has a list of authorized middlemen. Client sends fiat to a middleman with bank transfer, and the middleman will deposit CNY to the client's exchange account. It could be done within 30 minutes
...
Important question: can the middleman deposit more CNY into his own exchange account, or he already has the CNY in his account and only moves the required sum to the client's account? It works like the MtGox USD code or the BTC-E USD code. However, I suspect that some "middlemen" are actually employed by exchanges. |
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This is true: People have to transfer their money to a middle man first.
This is NOT true: It is still pretty hard to get money into exchange markets like Huobi, OKcoin and BTCChina.
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Dell accepting bitcoin could be MUCH bigger than you think http://ww4.sinaimg.cn/bmiddle/6d9e93aajw1eii0tf52tgj20hs0h6ac5.jpgAndy, a Chinese, shared his experience on Weibo (Chinese Twitter). With the 10% discount, he bought an Alienware 14 ( http://www.dell.com/us/p/alienware-14/pd.aspx) for 6442CNY in bitcoin The same item is selling at 11999CNY in China: http://item.jd.com/1107676.html . He saved 46% You may wonder why he couldn't buy it from dell.com directly before. Due to strict foreign exchange control, Chinese people could hardly have a "foreign currency credit card", and usual credit cards could not pay bills in USD or other foreign currency. As Dell now accepts bitcoin, Chinese people could order from dell.com directly, asking them to deliver to the US address of Haitao ( http://www.haitao.com/ ), who will then ship the item to China. This is only the beginning. But normal Joe Blogg's Chinese can't get Bitcoin easily. 46% discount should provide enough incentive for Joe Bloggs to open an account on huobi or okcoin. Despite China has banned bitcoin 10 times, I can tell you that, based on my first hand experience, Chinese people could still deposit fiat to exchanges in less than 30 minutes. That is correct. Care to give out detail on how an average citizen can do fiat deposit? What about withdraw? Exchange has a list of authorized middlemen. Client sends fiat to a middleman with bank transfer, and the middleman will deposit CNY to the client's exchange account. It could be done within 30 minutes Withdraw is same as before. Nothing has changed. |
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kinda ironic that the PC is prob made in china lol
I heard that Chinese earned 1 USD from each iPhone they made  |
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46% discount should provide enough incentive for Joe Bloggs to open an account on huobi or okcoin. Despite China has banned bitcoin 10 times, I can tell you that, based on my first hand experience, Chinese people could still deposit fiat to exchanges in less than 30 minutes.
In the latter part of 2013, Bitcoin skyrocketed arguably due to an increasing mudslide of Chinese capital that thought they had found a way of getting their wealth out the Chinese economy and turned into USD or whatever. The Chinese government put a stop to that....sure, they never banned Bitcoin outright, they just kind of disapproved of it and that was enough to send the majority of Chinese Bitcoiners packing. As and when the range of Bitcoin accepting merchants increases, authorities in China and indeed authorities all across the world will surely take measures to prevent their economies and tax collecting capacity is not undermined. Well, as I replied, Chinese authorities may still charge as high as 10% of import tax. Who cares 10% tax when you could save 46%? So this is a win-win situation: Joe gets a cheap laptop with 36% discount, and Chinese taxman gets paid |
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Dell accepting bitcoin could be MUCH bigger than you think http://ww4.sinaimg.cn/bmiddle/6d9e93aajw1eii0tf52tgj20hs0h6ac5.jpgAndy, a Chinese, shared his experience on Weibo (Chinese Twitter). With the 10% discount, he bought an Alienware 14 ( http://www.dell.com/us/p/alienware-14/pd.aspx) for 6442CNY in bitcoin The same item is selling at 11999CNY in China: http://item.jd.com/1107676.html . He saved 46% You may wonder why he couldn't buy it from dell.com directly before. Due to strict foreign exchange control, Chinese people could hardly have a "foreign currency credit card", and usual credit cards could not pay bills in USD or other foreign currency. As Dell now accepts bitcoin, Chinese people could order from dell.com directly, asking them to deliver to the US address of Haitao ( http://www.haitao.com/ ), who will then ship the item to China. This is only the beginning. But normal Joe Blogg's Chinese can't get Bitcoin easily. 46% discount should provide enough incentive for Joe Bloggs to open an account on huobi or okcoin. Despite China has banned bitcoin 10 times, I can tell you that, based on my first hand experience, Chinese people could still deposit fiat to exchanges in less than 30 minutes. |
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私钥对公钥不是顺序一一对应，那么就是说算完前2^160个私钥并不能找出所有公钥,因为里面可能会有很多组私钥只对应某些公钥，这我现在理解了。
但是顺序取用私钥和随机生成私钥去碰撞公钥有什么不同吗？概率还是一样的。
为什么这么做是一种最不可取的方法呢？能证明一下吗?
或者说你算一下用随机生成私钥的方法碰撞成功一个地址和循序遍历私钥的方法各会需要多少时间。
而且顺序计算不会发生随机生成私钥有可能把某些私钥重复生成计算的问题，虽说概率很小，但理论上确实会发生。而且随机生成私钥本身也需要代价，虽说代价很小。
顺序遍历是在没有任何其他更好的方法的情况下才采取的方法，只要有其他方法可以解决，就一定不会选择遍历，所以说这是最不可取的方法。 如果没有任何可行的方法，小样本空间下当然选择顺序取样，但如果样本空间大到一定程度，则随机取样更适合。 这是因为你不能假设你可以持续不断地连续取样，除非你能活的足够长（需要远远超过太阳系预计所能存活的时间）。 碰撞目标出现在2^159之后的概率至少有50%，如果顺序取样，那么，至少有50%可能性你算到银河系毁灭也100%碰撞不到。 随机取样就是为了避免出现这种情况而采取的手段。有得必有失，因为无法预估最终结果，所以就要承担一定的（可接受的范围）性能损失。 非常典型的概率謬誤, 就像賭徒以為彩票結果 "1,2,3,4,5,6" 比 "1,14,18,31,34,41" 更難出現, 其實兩者出現的概率完全一樣 無論是順序還是隨機嘗試, 成功的概率都是完全一樣. 单次取样的概率确实是一样的，但如果连续不断地取值，则随机取样有可能取出重复值（好的算法也只能是出现重复值的概率极低而已），因而效率略低于顺序取样。 采取随机取样是因为在有生之年以最大速度所能取到的样本数占总样本的比例仍几乎为0， 随机取样能覆盖的的范围会更广一些，所以仍有概率（虽然趋近于0）能取到。而顺序取样一旦选错了初始点，则100%碰撞不到。我已經講了一次, 這是很初級的概率謬誤. 順序取樣, 也有可能選到極好的初始點, 很快就碰撞成功. 因此很明顯, 無論是隨機取樣還是順序取樣, 所需計算量的期望值是完全一樣. |
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Dell accepting bitcoin could be MUCH bigger than you think http://ww4.sinaimg.cn/bmiddle/6d9e93aajw1eii0tf52tgj20hs0h6ac5.jpgAndy, a Chinese, shared his experience on Weibo (Chinese Twitter). With the 10% discount, he bought an Alienware 14 ( http://www.dell.com/us/p/alienware-14/pd.aspx) for 6442CNY in bitcoin The same item is selling at 11999CNY in China: http://item.jd.com/1107676.html . He saved 46% You may wonder why he couldn't buy it from dell.com directly before. Due to strict foreign exchange control, Chinese people could hardly have a "foreign currency credit card", and usual credit cards could not pay bills in USD or other foreign currency. As Dell now accepts bitcoin, Chinese people could order from dell.com directly, asking them to deliver to the US address of Haitao ( http://www.haitao.com/ ), who will then ship the item to China. This is only the beginning. |
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私钥对公钥不是顺序一一对应，那么就是说算完前2^160个私钥并不能找出所有公钥,因为里面可能会有很多组私钥只对应某些公钥，这我现在理解了。
但是顺序取用私钥和随机生成私钥去碰撞公钥有什么不同吗？概率还是一样的。
为什么这么做是一种最不可取的方法呢？能证明一下吗?
或者说你算一下用随机生成私钥的方法碰撞成功一个地址和循序遍历私钥的方法各会需要多少时间。
而且顺序计算不会发生随机生成私钥有可能把某些私钥重复生成计算的问题，虽说概率很小，但理论上确实会发生。而且随机生成私钥本身也需要代价，虽说代价很小。
顺序遍历是在没有任何其他更好的方法的情况下才采取的方法，只要有其他方法可以解决，就一定不会选择遍历，所以说这是最不可取的方法。 如果没有任何可行的方法，小样本空间下当然选择顺序取样，但如果样本空间大到一定程度，则随机取样更适合。 这是因为你不能假设你可以持续不断地连续取样，除非你能活的足够长（需要远远超过太阳系预计所能存活的时间）。 碰撞目标出现在2^159之后的概率至少有50%，如果顺序取样，那么，至少有50%可能性你算到银河系毁灭也100%碰撞不到。 随机取样就是为了避免出现这种情况而采取的手段。有得必有失，因为无法预估最终结果，所以就要承担一定的（可接受的范围）性能损失。 非常典型的概率謬誤, 就像賭徒以為彩票結果 "1,2,3,4,5,6" 比 "1,14,18,31,34,41" 更難出現, 其實兩者出現的概率完全一樣 無論是順序還是隨機嘗試, 成功的概率都是完全一樣. |
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按照公钥生成算法，在计算完 RIPEMD-160 哈希值后，有效位已经从256位减少到了160位，实际相当于有损压缩。
假如真有算力能支撑的话，只要顺序取前2^160个私钥进行运算，碰撞出公钥的概率也许会接近100%。
为什么一定要随机生成一个256位的私钥去碰撞呢？碰撞成功的概率会变大吗？
不知道我这么理解对不对？
当然实用地址生成不能这么做，这样别人就太容易循序找出私钥了。
不對，因為私鈅和地址不是一一對應，一個地址可能有多個私鈅，而且是隨機的 |
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计算bitcoin地址的描述不算太准确。 計算Bitcoin地址, 需要多種運算, 首先是生成一个256位的随机数，然后是一次ECC运算计算出公钥, 然后是一次HASH160(一次SHA256+RIPEMD160), 然后是一次HASH256(两次SHA256)，最后还有一次Base58编码。 我测试了一下，（CPU 2.6GHz，单线程运算）: 按挖矿模式（hash256并比对bits值），计算1000万个HASH256(block_header): 12秒; 计算出10万个地址及其私钥：94秒。 结论：計算一個私鑰对应的地址需要约800倍挖矿的計算量。 地址的校驗碼只是給人看的，可有可無，所以那個HASH256不用考慮 |
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