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## *The UASF community has announced if "the economic majority" is following BIP148 before August 1st, the UASF nodes will reject non-compliant blocks. This contentious attempt could leave miners confused and cause a chain split with a last minute hard fork. This is what a Sybil attack on Bitcoin looks like.*
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## What is Sybil and is Bitcoin under attack?
I reference this term very often; I am sure that others are familiar with this concept but may not be aware of the name. A Sybil attack is a concept in computer security and game theory where a network is subverted by a number of forged or fake identities. The name is from the book *Sybil* about a woman diagnosed with an identity disorder. Microsoft researchers had previously called this attack pseudospoofing.
In this attack, a malicious user subverts the reputation system of a network by controlling multiple identities in order to gain a disproportionately large influence. The attack surface of a network depends on how easy it is to generate accounts; what is the cost to generate an account? Does the system have a method of linking identities to a trusted source? Do all accounts have the same amount of influence? - without these things, it can be very easy for an attacker to control much more than his 'fair' share of influence.
Steem mitigates some Sybil attacks using their steem power system and vests. Without going too deep into steem's workings, it is the economic cost of 'freezing' assets in steem power that prevents abuse of the vote feature. A voter's weight is dependent on their incurred cost, *their stake*, in the network. This positions the economics such that users who use their own stake to vote for themselves must incur the economic cost and risk of keeping their steem locked up in steem power.
### The USAF Sybil
Some users in the Bitcoin community have expressed a desire to use open ports on their nodes to signal for a UASF or User Activated Soft Fork to enable SegWit. This soft fork is enabled through the nodes, which because they cost orders of magnitude less than mining equipment, are very easy for single actors to set up many of. This use of **node numbers to gauge support is a blatant Sybil attack on Bitcoin**. There is a reason that in Bitcoin, *hash-power is king*. I'll let the supporters of UASF explain:
>##### What is a UASF?
>UASF stands for User Activated Soft Fork. It’s a mechanism where the activation time of a soft fork occurs on a specified date enforced by full nodes, a concept sometimes referred to as the economic majority. A UASF requires a lot of industry support and coordination, which is good practice for eventual hard forks which requires, even more, industry coordination. In the past, a UASF was successfully carried out to activate the P2SH soft fork (BIP16). The UASF concept was combined with SegWit activation in the BIP148 proposal which can be found here: github.com/bitcoin/bips/blob/master/bip-0148.mediawiki.
-UASF.co
Their introduction is pretty good. BIP16 really was activated safely using this method. One exception, BIP16 was **not contentious**. This SegWit UASF that many Core developers are expressing their support of is absolutely contentious. When a UASF is contentious, it has all of the danger of a soft fork with the network effects (*chain splitting*) of a hard fork.
They also have set the activation threshold to be 51%, far below the general consensus standard of 75%. This industry-accepted 51% is also *not mandatory*. The activation happens only if the people in control, (*Core devs*), say so; the 51% is just a "good to have" goal set. They are looking for the vaguely defined: "economic majority".
This proposal has a large risk of splitting the network. If come August 1st (*the flag day*) and only a small minority hash power is following the BIP 148 chain, the blocks will be nearly impossible to mine until the 2016 blocks needed to readjust difficulty are mined. Users who do not support the user activated attempt can intentionally mine empty blocks on the SegWit chain - halting progress. Without some kind of "patch" turning everything into a last minute hard fork. See the response of Core developer Luke Dashjr to Medium user mpatc:
> **[mpatc]:** My apologies if this is part of the BIP and I overlooked it, but in the event of only a small minority hash following the BIP 148 chain, will there be some kind of emergency patch ready for the possibilities that:
>- Not enough hash power is mining the BIP148 chain and blocks become near impossible to mine for 2016 blocks and the difficulty finally readjusts.
>- non-BIP miners decide to point some of their hardware to intentionally mine empty blocks on the BIP148 chain.
>But unless I’m wrong, such a patch would be a hardfork out of necessity, and what we need to avoid at all cost?
> **[Luke Dashjr Responded]:** If we get to July and that seems like a risk, we can prepare a patch for these scenarios. **I don’t think we need to avoid a hardfork** at all costs
[-link to Medium post, emphasis my own](https://medium.com/@mpatc/my-apologies-if-this-is-part-of-the-bip-and-i-overlooked-it-but-in-the-event-of-only-a-small-153ee56965d6)
So if it looks like UASF is going to be the minority supported chain, the Core devs will prepare a hard fork patch to push SegWit through. This is dangerous. If their Sybil attack does not work, they are going to try and push through this half-baked and extremely contentious hard fork.
## Why would anyone want SegWit so badly?
So if it looks like only the minority supports SegWit after months of traditional mining support polling, why does Core want SegWit so badly? This is going to be based on much speculation so I urge readers to do their own research and comment their findings below.
**The BlockstreamCore Conspiracy**: investors have poured millions into the elusive blockchain company Blockstream who have been developing so-called "sidechain" or "layer two" solutions to scale Bitcoin. Their future revenue model depends on the Bitcoin main chain having scaling problems - promoting the use of their sidechain solutions. This is why Core has been so opposed to previous block size increases.
The kicker: their sidechains depend on SegWit to function. So Blockstream wants Bitcoin main net to be slow and congested because they want to promote layer two scaling solutions - but they need SegWit to do it! The hubris of Blockstream controlled Core devs: "we need years to plan a safe hardfork" meanwhile, "if our softfork does not work we will just throw together a hardfork at the last minute".
Hardforks are not what everyone makes them out to be. What they really are is full node referendums. They are *the* safest way to upgrade the protocol features of a blockchain. See my previous post [Hardfork: the tale of the full node referendum](https://steemit.com/cryptocurrency/@kyle.anderson/hardfork-the-tale-of-the-full-node-referendum)
>A full node referendum represents the explicit process where consensus can openly propagate a change. It does so whilst giving every user the choice to vote for or against the change. This ability for social consensus is an important facet of decentralized blockchains. A softfork distracts away from this social consensus by removing your ability to vote; the network will simply ignore your software, continuing on while you are unable to validate.
>In a full node referendum, it is ultimately up to you to choose to participate in the referendum. The referendum is transparent, open and hopefully useful, but in the end, it is ultimately up to you to choose to participate. If the social referendum is controversial, users are able to follow their principals as per Ethereum Classic. It is important that we avoid softforks or other protocol changes that could endanger the explicit choice of a full node referendum.
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#### Conclusion
If you don't support Core, don't run Core software, there are plenty of alternative Bitcoin implementations such as Bitcoin Classic, Bitcoin Unlimited, Bitcoin XT, bcoin and Parity Bitcoin.
Soft forks can lead to chain splits if they are not fully supported by the network.
Be skeptical of software that uses node numbers to judge support.
-Kyle
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##### If you are interested in blockchain, Bitcoin and science check out some of my other posts below:
[**Kim Dotcom knew Seth Rich, claims to have been involved with the Wikileaks submission - will give statement Tuesday**](https://steemit.com/wikileaks/@kyle.anderson/kim-dotcom-knew-seth-rich-claims-to-have-been-involved-with-the-wikileaks-submission-will-give-statement-tuesday)
[**Bitcoin search trends indicate momentum may continue - interest still rising**](https://steemit.com/bitcoin/@kyle.anderson/bitcoin-search-trends-indicate-momentum-may-continue-interest-still-rising)
[**What it is like riding Bitcoin bubbles: an adventure through the present cryptocurrency explosion**](https://steemit.com/bitcoin/@kyle.anderson/what-it-is-like-riding-bitcoin-bubbles-an-adventure-through-the-present-cryptocurrency-explosion)
[**Julian Assange celebrates victory from Ecuadorian embassy balcony after months of absence - comments on rape charges dropped by Sweden**](https://steemit.com/wikileaks/@kyle.anderson/julian-assange-celebrates-victory-from-ecuadorian-embassy-balcony-after-months-of-absence-comments-on-rape-charges-dropped-by)
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