BIP91 locked-in

Bitcoin Improvement Proposal 91 is now locked in
21 July 2017   2137



Distributed database that is used to maintain a continuously growing list of records, called blocks

Segregated Witness, defined by BIP141, locks in if at least 95% of miners signal support for the upgrade within a two-week difficulty period. In order to do so, miners need to embed a piece of data called “bit 1” in the blocks they mine. This is technically the only way for SegWit to be activated right now. 

However, there are some alternative strategies to reach this threshold “indirectly” — those like BIP91.

BIP91 is a Bitcoin Improvement Proposal adopted due to the New York Agreement and supported by a number of Bitcoin companies and mining pools. 

What happened?


Is the first decentralized peer-to-peer payment network that is powered by its users with no central authority or middlemen

Bitcoin Improvement Proposal 91 (BIP91) has just locked in as up to 90% of all hash power signaled support for this softfork signaled in support of this decision. The next step is to be the activation of Segregated Witness (SegWit). As a result, this should make BIP148 obsolete and the risk of chain split on August 1st will be avoided.

Proposal Activation SpotlightProposal Activation Spotlight by

Thus, miners have been signaling support for BIP91 over the past couple of days through another piece of data, “bit 4.” Once 269 blocks within a 336-block window include bit 4, this BIP91 soft fork gets locked in. And this is exactly what just happened.

What's next

After another 336 blocks, a little over two days from now, all BIP91-compatible nodes will reject any block that doesn’t include bit 1.

As long as a majority of hash power enforces BIP91, this majority should eventually control the longest valid chain according to all Bitcoin nodes. And as this chain consists of bit 1 SegWit-signaling blocks only, it would in turn activate SegWit on all SegWit-ready nodes.

In this case, BIP141 should lock in by mid-August, and SegWit should be live on the Bitcoin network after a two-week “grace period” by the end of the month.

Japan to Tighten Regulation Due to Zaif Hack

$ 62 000 000 worth cryptocurrency was stolen from the Zaif exchange few weeks ago
25 September 2018   83

Hacking of Zaif exchange is the reason for toughening control over the market by the financial regulator of Japan, Reuters reports.

The first measure taken was administrative sanctions against the exchange and its operator Tech Bureau Corp. The Financial Services Agency (FSA) has expanded the list of requirements for the latter, pointing out the need to identify preventive measures and search for the organizers of the theft.

Shortly before that, researchers of the Japanese financial company Tech Bureau Corp could not provide details of the theft of $ 62 million from the Zaif crypto exchange at the request of the FSA. The Osaka-based operator had to investigate the causes, consequences of the theft and options for compensating the victims. According to the Agency, the financial company could not cope with the task.

According to the Tech Bureau, the exchange was hacked on September 14 within a few hours. The problem with the server was discovered by the site staff on 17 September. Official confirmation of the incident and notification of the authorities was made only a day later.

Recall, the theft of $ 60 million from the Japanese stock exchange Zaif caused a surge of volatility of bitcoin. For a short time the price was able to overcome the distance of $ 400.