Well here we are, August 1st, 2017.
Unless you been sleeping under a rock you know that this date has been talked about for the past 2 months as some sort of milestone for Bitcoin. Depending on your viewpoint it is either the Apocalypse or the salvation of Bitcoin. While the outcome is probably somewhere in-between these two extremes, lets look at what to expect today.
Midnight 00:00 UTC
Launch of the BIP 148 UASF.
Since miners are already enforcing BIP 91 on the main bitcoin network, this should not cause any concerns. This means that BIP 148 will basically have no effect and Bitcoin will continue on as a single chain, in other words no UASF fork.
12:20 PM UTC (8:20 AM EST)
Launch of Bitcoin Cash (BCC).
Any miners who plan to support the Bitcoin Cash (BCC) currency will need to switch over their mining hash power at this point to the BCC chain. At least 1 pool, ViaBTC is already operational and ready to let miners begin hashing on the new chain at this exact point in time. Any miners mining at the pool before 12:20 PM UTC will not be wasting their hash power as mining will continue on the Bitcoin (BTC) chain until then.
While Bitcoin Cash (BCC) is using the Bitcoin (BTC) chain as a starting point, this is not quite the same as a typical hard fork, but instead is rather more like the launch of an alternative cryptocurrency.
After the first block on the Bitcoin Cash (BCC) chain is mined, anyone who controls their private keys on the BTC chain will now have two currencies. They will own their original amount of Bitcoin and an equal amount of the new Bitcoin Cash. Exact details on how to obtain Bitcoin Cash (BCC) will be forthcoming as the chain comes online and the first blocks are mined.
Also note that if you do not control your private keys, i.e. your funds are on an exchange, you will need to inquire to your exchange if they plan to support Bitcoin Cash (BCC) or not.
I have added a listing of exchanges planning to support Bitcoin Cash (BCC) at the bottom of this post (expect this list to change).
12:20 PM – 1:30 PM UTC (8:20 AM – 9:30 AM EST)
Bitcoin Cash (BCC) will not launch instantly at 12:20 PM UTC, but instead miners will begin mining blocks on that chain following BCC’s rules. It will take some time for the first block to be mined which is the foundation of the BCC split.
This could be anywhere from minutes up to an hour or two afterwards depending upon luck and the amount of hashing power that the Bitcoin Cash (BCC) chain actually receives.
The following quote from the Bitcoin Cash website offers a more formal specification for activation of the fork:
The criterion for activation of the Bitcoin Cash hard fork activation is based on “Median Time Past”, or MTP. This means that the chain split will not occur at exactly 12:20 UTC on Aug. 1st, but some time after.
MTP is a statistic calculated over 11 blocks, and trails behind wall clock time by about 6 blocks. This means that the last common block will be approximately the 6th block with a timestamp after 12:20pm. The block after that will be different on either chain.
Since Bitcoin is mined at a rate of roughly 6 blocks per hour (10 minute block times), in theory this would mean 1 hour later, or around 1:20 PM UTC. However, depending on how much, or how little, hash rate the BCC chain initially receives will largely determine how fast it will activate.
Update: We are now past the cut-over time for the Bitcoin Cash (BCC) fork and miners are actively mining on the BCC chain. Due to the reduced hash-rate (see explanation earlier) on the BCC chain compared to the BTC chain, this might take some time yet for the first valid BCC block to be mined. The split happened around 12:37 PM UTC (8:37 AM EST) at block number 478,558. The BCC chain now needs to mine a block larger than 1 MB for the split to lock in.
In essence, the Bitcoin Cash fork inherited the Bitcoin difficulty level which was based upon roughly 6,400 Petahash/second of mining power (the amount of hash rate at the time of the split) that would maintain an average of a block being found once every 10 minutes. As of this update the Bitcoin Cash network is only receiving about 200 Petahash/second from miners, or roughly 1/32 that of Bitcoins.
The Bitcoin Cash developers foresaw this eventuality and implemented a change in BCC’s code that would lower the difficulty by 20% if 6 blocks are not found within a 12 hour time-span. This would effectively let the difficulty adjust over time to match the hash-rate that miners eventually point to the Bitcoin Cash chain. The catch is, the BCC chain needs to mine 6 blocks for this mechanism to kick in, with the greater than 1 MB block being considered the first block on the new chain.
You will be able to keep an eye on the Bitcoin Cash block progress at: https://cash.coin.dance/ once this first BCC block is mined and the fork has been activated.
So what are some of the difference Bitcoin Cash has compared to Bitcoin? According to the BCC website, a few advantages include:
- Block Size Limit Increase – Bitcoin Cash provides much needed relief to users with an immediate increase of the block size limit to 8MB.
- Replay and Wipeout Protection – Should two chains persist, Bitcoin Cash minimizes user disruption, and permits safe and peaceful coexistence of the two chains, with well thought out replay and wipe-out protection.
- New SigHash Type – As part of the replay protection technology, Bitcoin Cash introduces a new way of signing transactions. This also brings additional benefits such as input value signing for improved hardware wallet security, and elimination of the quadratic hashing problem.
Notably missing from the list however is the removal of Segregated Witness (SegWit) support. Since the BCC can scale the block size up to 8 MB there is no need for the SegWit solution at all they feel.
Not surprisingly, this was one of the main sticking point between the two camps, so for the most part you can consider BTC as the SegWit chain and BCC as the 8 MB chain.
The proposed ticker symbol for Bitcoin Cash, BCC, is already in use by BitConnect Coin. Some people are suggesting to use the ticker symbol BCH (abbreviation for Bitcoin CasH) instead.
I have used BCC on this site so far to signify Bitcoin Cash, but just be aware that there is some contention for the ticker symbol and it may change in the future. That is one of the reasons I am going out of my way to signify when I am talking about Bitcoin (BTC) and Bitcoin Cash (BCC) with both the name and ticker symbol to try and avoid confusion.
So the main takeaway is if you plan on trading Bitcoin Cash on any exchanges just double check the name and not rely on just the symbol.
Current Exchange Stance on Bitcoin Cash Support
Note that this list is current as of this moment in time and will likely change, possibly rapidly as events unfold.
- Bitfinex – will credit Bitcoin Cash, unknown for trading
- Bitstamp – no plans to offer Bitcoin Cash support
- Bittrex – will credit Bitcoin Cash, may add trading at a future point
- Coinbase – no plans to offer Bitcoin Cash support
- Cryptopia – no plans to offer Bitcoin Cash support
- GDAX – no plans to offer Bitcoin Cash support
- Gemini – no plans to offer Bitcoin Cash support
- Kraken – will credit Bitcoin Cash and plans to offer trading
- Poloniex – no plans to offer Bitcoin Cash support
- Shapeshift – no plans to offer Bitcoin Cash support
- ViaBTC – will credit Bitcoin Cash and plans to offer trading