Summary
Your bitcoins are safe if you received them in transactions confirmed before 2015-07-04 15:00 UTC.
However, there has been a problem with a planned upgrade. For bitcoins received later than the time above, confirmation scores are significantly less reliable then they usually are for users of certain software:
- Lightweight (SPV) wallet users should wait an additional 30 confirmations more than you would normally wait.
- Bitcoin Core 0.9.4 or earlier users should wait an additional 30 confirmations more than you would normally wait or upgrade to Bitcoin Core 0.10.2.
- Web wallet users should wait an additional 30 confirmations more than you would normally wait, unless you know for sure that your wallet is secured by Bitcoin Core 0.9.5 or later.
- Bitcoin Core 0.9.5 or later users are unaffected. (Note: upgrade to 0.10.2 is recommended due to denial-of-service vulnerabilities unrelated to this alert.)
[More after the break.]
The incident status page describes the cause of the problem:
For several months, an increasing amount of mining hash rate has been signaling its intent to begin enforcing BIP66 strict DER signatures. As part of the BIP66 rules, once 950 of the last 1,000 blocks were version 3 (v3) blocks, all upgraded miners would reject version 2 (v2) blocks.
Early morning UTC on 4 July 2015, the 950/1000 (95%) threshold was reached. Shortly thereafter, a small miner (part of the non-upgraded 5%) mined an invalid block--as was an expected occurrence. Unfortunately, it turned out that roughly half the network hash rate was mining without fully validating blocks (called SPV mining), and built new blocks on top of that invalid block.
It further describes the impact of this on Bitcoin users:
All software that assumes blocks are valid (because invalid blocks cost miners money) is at risk of showing transactions as confirmed when they really aren't. This particularly affects lightweight (SPV) wallets and software such as old versions of Bitcoin Core which have been downgraded to SPV-level security by the new BIP66 consensus rules
There has already been lost revenue as a result of this incident, with the status page stating "several large miners have lost over $50,000 dollars worth of mining income so far." The status page will be updated as this situation unfolds. There is currently a big red warning message at the top of their status page that prominently states: "many wallets currently vulnerable to double-spending of confirmed transactions."
[Update: corrected links to 0.10.2 - Ed.]
(Score: 2, Informative) by rigrig on Sunday July 05 2015, @11:29AM
There is no "break" or "fold"
Only the bit above [More after the break.] shows up on the front page and in the RSS feed.
No one remembers the singer.
(Score: 2) by Justin Case on Sunday July 05 2015, @11:55AM
Interesting hypothesis, thank you.
However the RSS feed I'm getting has the whole summary... curiously minus the self-referencing "break" message. I checked view-source of the RSS message and nope, it isn't even hidden.
That leaves the front page as a valid use case. So maybe the "more" message should be in the front page software, not the article text which as we now see, goes several places?
(Score: 3, Informative) by martyb on Sunday July 05 2015, @01:11PM
Yes, as you surmised this is an artifact of the UI and our best current efforts at a workaround. When editing a story, there are two places in which the story text can be placed: "Intro Copy" and "Extended Copy."
When you load the main page of the site https://soylentnews.org/ [soylentnews.org], only the text which is in the "Intro Copy" area is displayed. One needs to click on one of the links below the story (e.g. the "Read More..." button or the "n Comments" link) in order to see the text in the "Extended Copy" part of the story.
If one does not notice the additional link below the story (in this case it reads "441 words in story"), then one could get the mistaken assumption that there is nothing more to the story. Though redundant in some cases, we have chosen to include some text along the lines of "[More after the break...]" to make this abundantly clear. The motivation is that we had several cases where discussions went sideways with hypotheses that were already answered in the "Extended Copy" text! This part of the UI admittedly requires some work. I have some ideas, but need to put it into writing and submit it to the devs.
By the way, there is another place where the "Extended Copy" does not appear -- in the e-mails sent out with the day's stories. Registered users can request this e-mail in your preferences.
Lastly, if you are aware of any other places in the UI where this might be an issue, I would very much appreciate your replying to this comment with that info so I can include it in the rework.
Wit is intellect, dancing. I'm too old to act my age. Life is too important to take myself seriously.
(Score: 2) by ticho on Sunday July 05 2015, @02:37PM
It's simple - get rid of the concept of two copies entirely. It is useless, as GP has mentioned.
(Score: 2) by martyb on Wednesday July 08 2015, @12:19PM
Useless? Imagine these stories appearing on the main page, in their entirety:
Some people may not find those stories interesting. Imagine that you need to scroll through those walls of text in order to get to the next story. Also consider that not everyone is viewing this site on a desktop monitor or large tablet; I know of at least one person who regularly reads the site using the 320x240 display on their mobile phone.
I see the ability to present a portion of the story, and provide access to the rest of the story as a desirable feature for the site. As for the implementation? I'm with others on that one in that it could use some work.
Wit is intellect, dancing. I'm too old to act my age. Life is too important to take myself seriously.