Hi Tim,

    Really glad to see you have posted on bitcointalk about your coins!

    Trust issues with centralisation aside this is a different approach to Casascius and I think it could have a place in the market.

    Can one buy via your website now?

1. Why do these have serial number printed onto the holograms?


2. Can you expand more on the laser engraving and how this will add security?

3. To clarify: do you mean the addresses prefixed with "LTCX" will never be used so are being removed from your list?

And now its fallen around a third in value.  Any insights?

Some questions:

1. Will you be doing other denominations of your physical XPM, CGB and PPC?

2. Any chance of increasing the denominations for the first release of the physical PPC? (I would be happy to pay a bit extra to cover this).

3. If successful will you be producing more physical XPM, CGB and PPC in greater quantities after this initial batch?

gigatux: If I've signed up, verified my mobile and provided proof of name and address what is the most BTC I can purchase per day?

Correct me if I am wrong but isn't the MTGOX twitter account now confirmed as fake?

Running low on 5s - first come first serve.

I’ve had a look around and can’t find an answer to this.

Is it possible to attack the current Bitcoin blockchain with a competing blockchain that is longer than it?

For example to attack the current blockchain within the timespan of roughly a quarter of its current lifetime you would:

    1. Work out the length of the current blockchain to be attacked.
    2. Work out the maximum hashing power of the hardware you wish to use to generate the new blockchain.
    3. Recursively divide the hashing power of the hardware by four for each difficulty adjustment the current blockchain has undergone. E.g. if you have a hashrate of  640 KHs and the blockchain has undergone 3 difficulty adjustments you would calculate 640KHs/4^3 = 10KHs.
    4. Start generating the new blockchain from the genesis block, starting with the lowest calculated hashrate. For this example 10KHs.
    5. Each time the blockchain’s mining difficulty is re-calculated the hardware then applies four times as much hashing power to solving the next 2016 blocks. The effect of this will be to generate blocks in a quarter the target time the current blockchain was generated. E.g. the first 2016 blocks will be hashed with a hashrate of 10Khs, as soon as the difficulty re-adjusts the next 2016 blocks are then hashed with a hashrate of 40KHs, then 160KHs at the next difficulty adjustment, and 640KHs at the fourth adjustment.
    6. Once a the new blockchain, longer than the current blockchain has been generated, the attacker can propagate it across the network, replacing the current blockchain.

(For simplicity I have assumed that the current blockchain does not continue to grow whilst the hardware is generating a new block chain in reality you would assume a longer generation time than that of the current blockchain if you wanted to launch an attack).

Assumptions:

    1. Blocks can be mined with an extremely low hashrate.
    2. The Bitcoin network favours the chain of the longest length. (I may be wrong here and it may infact favour the chain of the greatest average difficulty).
    3. Each network difficulty adjustment adjusts the block generation time back to the average target (10 minutes in the case of Bitcoin) and that for each adjustment there are no maximum or minimum levels by which it can be adjusted per readjustment.

Unknowns:

Could a new blockchain be generated in a similar manner to above to attack a Proof of Stake (PoS) blockchain in the following manner:

In the future, where there has been significant improvements in hashing power and assuming the network does judge blockchain preference on average difficulty of the blocks generated, could an attacker generate a new PoS blockchain from the genesis block on separate hardware, then when it exceeds the current PoS blockchain release this to the network to overwrite the current PoS blockchain?

If the PoS blockchain selection were then to rely on transaction volume to try and mitigate this for example it could still be fooled by a basic sybil attack, so a Proof of Work or PoS mechanism could be needed to mitigate this.

Can anyone clarify the above and any assumption I may have made?

From what I gather from this Wikipedia article PPC has both interest payment and is inflationary, that is money held in savings has it's value eroded by the production of more PPC:

http://en.wikipedia.org/wiki/PPCoin

Can anyone clarify the specifics of these two mechanisms; I'm not able to read the PPC source code natively so need to understand this from a functional implementation perspective.

So how much does Novacoin pay? Any specific sources of info you can point me at for this?

How does eMunie judge inflation? Is it done centrally or in a decentralised way?

Apart from CryptogenicBullion are there any other cryptocurrencies that pay interest on funds held:

Been over 24 hours and still no broadcast from MTGOX to the network for my transfer despite two emails to support...

Getting worried now.

Eight hours later and MTGOX still has not broadcast my transfer of BTC.

From MTGOX technical support:


Depending on how many piers each node is connected to transaction broadcasts are almost instant (a few milliseconds) and I would definitely expect instant broadcasts from an entity the size of MTGOX with its own mining farm.

This is starting to move into the realm of deliberately giving misguiding information to customers and that worries me greatly.

Again; I am withdrawing and nothing is being broadcast that can be seen by cryptsy or blockchain.info for nearly half an hour now.

I hope it is just an issue of cold storage retrieval.

Either way this is pretty bad.

https://blockchain.info/address/18qBHR26QbHyyW9PRSHFNEcZtXGyXQxCCD

So what exchanges currently allow one to buy CGB?

Why is that an advantage? I'm not saying it isn't but I'm curious to know if there is a consensus on this...

Oh, and FiniteByDesign can we have window or numbers printed across the holograms on the coins showing the starting characters blockchain addresses this time if possible?

I'd be potentially interested, still trying to find a good source of info on the specific advantages of CGB. Can anyone point me at a link?

Are there any plans to add Cryptogenic Bullion to Vircurex?