Bittylicious Blog

Syscoin now on Bittylicious

Sep
15

white-logo-640x130-e1459111923427Syscoin is now available for sale on Bittylicious. Presently, it is available to UK users via bank transfer but we intend on making it available to users buying via credit/debit card, and thus available globally.

Syscoin has a very active development team and is ranked 35th on CoinMarketCap. Consistently, they are a top-ten coin on both Poloniex and Bittrex.

syscoin

Quark gone and Maxcoin at risk

May
25

Spring is approaching and it’s time for our spring tidy up of coins that people no longer are interested in.

There have been no sales whatsoever of Quark this year, and sadly with the recent warnings of low volumes, this coins is being removed immediately.

Maxcoin is also at risk, with three sales totaling less than £60 year to date. Maxcoin has had an extremely turbulent ride, but I believe part of its decrease in popularity has been due to the increase in popularity of StartCOIN. Maxcoin will be removed in about a month assuming no significant increase in sales.

Ether (Ethereum) for sale

Nov
18

From Monday 23rd November, Bittylicious will be allowing users to buy Ether, the currency of the Ethereum project, on the Bittylicious platform. This will be available via the following payment methods:

  • UK bank transfer
  • SEPA
  • Credit / debit cards

Ethereum is much more than a next-generation cryptocurrency. It is a distributed, Turing Complete programming platform, which uses a cryptocurrency as its “fuel”. Many believe that this is the logical evolution of Bitcoin-style cryptocurrencies and that it has a very bright future. Ether is the fuel this platform uses, which is used when processing smart contracts on the platform. From an investment perspective, some believe that the widespread use of this platform will make the value of Ether very high in the future.

Transaction Malleability

Oct
12

Transaction malleability is once again affecting the entire Bitcoin network. Generally, this causes a lot of confusion more than anything else, and results in seemingly duplicate transactions until the next block is mined. This can be seen as the following:

  • Your original transaction never confirming.
  • Another transaction, with the same amount of coins going to and from the same addresses, appearing. This has a different transaction ID.

Often, this different transaction ID will confirm, and in certain block explorers, you will see warnings about the original transaction being a double spend or otherwise being invalid.

Ultimately though, just one transaction, with the correct amount of Bitcoins being sent, should confirm. If no transactions confirm, or more than one confirm, then this probably isn’t directly linked to transaction malleability.

Change outputs

However, Bittylicious noticed that there were some transactions sent that have not been mutated, and also are failing to confirm. This is because they rely on a previous input that also won’t confirm.

Essentially, Bitcoin transactions involve spending inputs (which can be thought of as Bitcoins “inside” a Bitcoin address) and then getting some change back. For instance, if I had a single input of 10 BTC and wanted to send 1 BTC to someone, I would create a transaction as follows:

10 BTC -> 1 BTC (to the user) and 9 BTC (back to myself)

This way, there is a sort of chain that can be created for all Bitcoins from the initial mining transaction.

When Bitcoin core does a transaction like this, it trusts that it will get the 9 BTC change back, and it will because it generated this transaction itself, or at the very least, the whole transaction won’t confirm but nothing is lost. It can immediately send on this 9 BTC in a further transaction without waiting on this being confirmed because it knows where the coins are going to and it knows the transaction information in the network.

However, this assumption is wrong.

If the transaction is mutated, Bitcoin core may end up trying to create a new transaction using the 9 BTC change, but based on wrong input information. This is because the actual transaction ID and related data has changed in the blockchain.

Hence, Bitcoin core should never trust itself in this instance, and should always wait on a confirmation for change before sending on this change.

Mitigation steps on Bittylicious

We have configured our primary Bitcoin node to no longer allow change, with zero confirmations, to be included in any Bitcoin transaction. This was configured by running bitcoind with the -spendzeroconfchange=0 option.

This is not enough though, and this can result in a situation where transactions cannot be sent because there are not enough inputs available with at least one confirmation to send a new transaction. Thus, we also run a process which does the following:

  1. Checks available, unspent but confirmed inputs by calling bitcoin-cli listunspent 1.
  2. If there are less than x inputs (currently twelve) then do the following:
    1. Work out what input is for around 10 BTC.
    2. Work out how to split this into as many 1 BTC transactions as possible, leaving enough space for a fee on top.
    3. Call bitcoin-cli sendmany to send that ~10 BTC input to around 10 output addresses, all owned by Bittylicious.

This way, we can convert one 10 BTC input into approximately ten 1 BTC inputs, which can be used for further transactions. We do this when we are “running low” on inputs and there twelve of less remaining.

These steps ensure that we will only ever send transactions with fully confirmed inputs.

Fixing old transactions

One issue remains though – before we implemented this change, some transactions got sent that rely on mutated change and will never be confirmed.

At present, we are researching the best way to resend these transactions. We will probably zap the transactions at an off-peak time, although we want to itemise all the transactions we think should be zapped beforehand, which will take some time.

Other techniques to decrease the impact

One simple technique to decrease the chances of malleability being an issue is to have your Bitcoin node to connect to as many other nodes as possible. That way, you will be “shouting” your new transaction out and getting it popular very quickly, which will likely mean that any mutated transaction will get drowned out and rejected first.

There are some nodes out there that have anti-mutation code in already. These are able to detect mutated transactions and only pass on the validated transaction. It is useful to connect to trusted nodes like this, and worth considering implementing this (which will come with its own risks of course).

The future, from a Bitcoin perspective

All of these malleability issues will not be a problem once the BIP 62 enhancement to Bitcoin is implemented, which will make malleability impossible. This unfortunately is some way off and there is no reference implementation at present, let alone a plan for migration to a new block type.

Although only brief thought has been given, it may be possible for future versions of Bitcoin software to detect themselves when malleability has occurred on change inputs, and then do one of the following:

  • Mark this transaction as rejected and remove it from the wallet, as we know it will never confirm (potentially risky, especially if there is a reorg). Possibly inform the node owner.
  • Attempt to “repackage” the transaction, i.e. use the same from and to address parameters, but with the correct input details from the change transaction as accepted in the block.

It may be the case that the above is impossible, as these really are just rambling thoughts.

Credits

Written by Marc Warne of Bittylicious.

Assistance and good chat from iwilcox, midnightmagic and Victorsueca of the #bitcoin IRC channel.

Bittylicious is two years old today

Jun
20

It has been exactly two years since Bittylicious was first announced to the public on BitcoinTalk.

Back then, Bittylicious was a simple service with all sales being done by just one person. You could only buy Bitcoins for UK bank transfers, the limits were quite low, and most things were manual.

Bitcoins only cost around £70 each back then, and the regulatory environment was totally unknown. There was a lot of fear about needing to be regulated by the FCA (FSA back then), worries about VAT being charged and fears about banks shutting down accounts. Alas, the last worry is still one to this day.

It became apparent that if Bittylicious were to survive, it would need to evolve into a marketplace so that multiple bank accounts could be used and, in theory, cheaper prices could be achieved if there were competition. This was clearly the correct decision to make.

Two years on and Bittylicious is multi-seller, multi-payment method, multi-country, multi-currency, multi-altcoin and multi-direction. The fraud environment has changed significantly, as has the general recommendations for AML and KYC, so Bittylicious constantly needs to evolve. Bittylicious is developed to this day, and even two years on, this is just the beginning.

To the moon!

Worldcoin removed. Quark and Blackcoin at risk

Jun
18

Sadly, we have now removed Worldcoin from Bittylicious because of consistently low sales. There was a good effort from one Worldcoin member to get some volume through, but sadly this was not sustainable.

Quark and Blackcoin are both suffering very low volumes at present as well, and are thus both at risk of being removed. Peercoin has fared a lot better over the last three months and is now back in the safe zone.

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Bittylicious Brokers are the Nicest

Jun
12

2015-06-11 12.59.43Bittylicious users often enjoy pretty good rates, exceptionally quick purchases and brilliant customer service, but we would just like to toot our own trumpets a little by saying just how darned well nice the brokers on the platform are.

The main admin (Marc) helped out one of the brokers who was having issues with their bank account being frozen. Marc wrote a letter to the bank stating that his transactions were legitimate. In part because of this, the broker’s bank account was made available again. As a wonderful gesture of thanks, this broker sent Marc some lovely jamón brought all the way back from Spain. Yum!

Sometimes issues happen, often caused by external services such as banks. The first line of support is the brokers, who pass issues up the chain if needed. These are the guys and girls that keep the Bittylicious platform running so well, and they’re a really decent bunch of people. Bravo!

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Bittylicious featured in MoneyWeek

Jun
11

This week’s cover story for Money Week is a well written article by Dominic Frisby that talks about Bitcoins. It quite rightly states that Bitcoins, and blockchain technology, will drive the money revolution.

There is a good background showing that it marries cash with classic digital money, proof that it works (see how the black markets fare!) and then talks briefly about the future including smart contracts.

On page 26, the final page of the cover story, Dominic talks about how to actually get Bitcoins, with Bittylicious being the main site mentioned here:

“Go to bittylicious.com. Paste your wallet address
where it says “bitcoin address”, then deposit some money.”

Dominic published his book, Bitcoin – The future of money? in November 2014 and it’s gotten some excellent reviews. We’ve just ordered our copy.

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Vertcoin now removed, Worldcoin to follow

May
18

Sadly, we have removed Vertcoin for sale from Bittylicious because of a lack of demand. The last sale was on 9th February 2015.

It is looking like Worldcoin will be the next to go, with the last sale on 29th March 2015 and only £454 worth of sales in the last three months. Quark and Peercoin are faring a little better, but are still at risk.

Bittylicious needs to, from time to time, purge coins that are no longer in demand. Each coin on Bittylicious takes up significant resources and stops being sustainable once demand drops to a low level.

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NuBits now on Bittylicious

Apr
29

NuBits is the latest cryptocurrency to be listed on the Bittylicious platform, and it is available to buy via UK bank transfer and SEPA bank transfers across Europe.

The most interesting feature about NuBits over most other cryptocurrencies is its focus on price stability. One NuBit is intended to cost a certain price, and this is reflected on Bittylicious with one NuBit being $1 USD (converted into the appropriate British Pound or Euro price). There is a dedicated page on the NuBits site saying how this is achieved.

In the pipeline, we aim for NuBits to also be made available via credit and debit card purchases and we are actively investigating other ways this can be made available easily.

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