Xoroshiro128++ Guessing Order Optimization Project
You may have noticed some new workunits hit the queue. As of the time of writing, the workunits that are available should be considered "beta" as we're working out a few kinks.
That said, this is a new CPU app! As time goes on, we'll be replacing configuration files for it to further refine the results, so work will be sent out in stages and we'll feel out how much workunits make sense for each stage.

I've included a fairly technical explanation from the primary author of the app, MC, longtime contributor to Minecraft@Home:

The Xoroshiro Guessing Order project aims to uncover exploitable statistical weaknesses in the xoroshiro128++ pseudorandom number generator (PRNG). Recent versions of Minecraft now use xoroshiro128++ for specific aspects of world generation, replacing Java's default PRNG. Unfortunately, this shift creates significant challenges for seedcracking projects, as no efficient algorithm currently exists to reconstruct the internal state of xoroshiro from its outputs.

Our primary goal is to develop a reliable method for recovering the PRNG's 128-bit seed from just two sequential 64-bit outputs. Currently, the most efficient known method (excluding SAT solvers) involves guessing 54 bits of the state, after which the remaining bits can be derived, a process requiring roughly 9 quadrillion attempts on average. Our aim is to significantly reduce this computational requirement.

Xoroshiro128++ belongs to the "xorshift" family of PRNGs, which means its core operations are linear. The internal state can therefore be represented as a binary vector within a 128-dimensional vector space, with state transitions represented as matrix multiplications. However, the primary challenge arises from its use of a non-linear "scrambler" function, which maps the internal state to its output. Due to this scrambler, there is no straightforward one-to-one relationship between the 128-dimensional internal state and the 128-bit output.

Fortunately, the scrambler function is imperfect. Most of the information provided by each output bit is concentrated in a relatively small subset, approximately a dozen dimensions, of the total 128-dimensional state. Even with a partial, lower-dimensional guess of the state, it is frequently possible to determine whether the guess is incorrect based on the known output. If we can identify low-dimensional subsets of the state space that are significantly constrained by the outputs, we can efficiently guess and verify these smaller portions first, rapidly eliminating incorrect possibilities.

Participants in our project analyze these lower-dimensional subsets of the state space, identifying those subsets most constrained by observed outputs. To facilitate this process, we use a large precomputed table that estimates the amount of information (in bits) xoroshiro's output data provides about each subset of state dimensions.

By ultimately identifying an optimal sequence of highly constrained subspaces, we can incrementally guess the state one dimension at a time, discarding incorrect possibilities early on. Achieving this optimal guessing order would produce a highly efficient algorithm capable of recovering the PRNG's internal state within a small number of attempts, significantly advancing future efforts in Minecraft seedcracking and related research.
29 Mar 2025, 5:56:02 UTC · Discuss

Loneliest Seed v1.08
Hi folks!

I know it's been a bit, life gets in the way sometimes. However, I've released v1.08 of the Loneliest Seed project which aims to address the checkpointing issue.

We're experimenting with a CPU project separate from this as well, so stay tuned for that! If the experiments go well on our end we're anticipating launching a CPU app that will aid us in our years-long research into finding methods of reversing PRNG states in the Xoroshiro128++ algorithm.

Best regards,
Minecraft@Home Team
26 Mar 2025, 15:09:17 UTC · Discuss

High error rate on 'Loneliest Seed' tasks for older GPUs
Hi everyone,

I wanted to put this out there as I'm seeing a high error rate on tasks running on older GPUs.

I've spent a chunk of time digging into these, and the most prevalent error is a launch timeout error from the cuda driver.
This is a possible indication of either hardware failure, or a buggy driver.

If you see a lot of "Error 702" failing tasks, please update your drivers to the latest possible for your OS and video card, as there's potentially an issue with your current driver preventing work from completing on your card.

Please let us know if you have any questions, or need any help determining the issue.

Thanks!
17 Jan 2025, 5:02:26 UTC · Discuss

The Loneliest Seed
Hi Folks!

We're back with another round of tasks. This time for Nvidia GPUs.

The first batch will have 262144 workunits (524288 tasks), but we anticipate that there will be far more in the future for this project fed in gradually. (Estimated 17.1 billion workunits possible).

Apologies for the lack of communication/delays the last few months. These days I'm the primary administrator on this project, and while I do pay attention to our discord more, I should do better to keep the community on the BOINC platform in the loop about future updates.

Beyond this project, we may have one other lined up (much smaller in scope than this 17.1 billion workunit project) and an overall platform upgrade that I've slowly been widdling away at these last few months as I find time.

I'll be pushing the new work tonight, so get your GPUs ready! They're available on Windows and Linux x86_64 machines.

Best Regards,

BoySanic
12 Jan 2025, 3:57:41 UTC · Discuss

Minecraft@Home is Back with New CPU Work – Get Involved Before It's Gone!
We’re excited to announce that Minecraft@Home has returned with fresh CPU-based workunits! However, just like the Minecraft universe itself, our computing needs can shift rapidly. While the current tasks are available now, they won’t last forever, so we encourage everyone to get involved while you can.

At Minecraft@Home, our projects vary over time, and sometimes we don’t need as much (or any) computing power. This is one of those moments where we have specific tasks ready for processing, but once they’re completed, the work will wrap up—until our next big discovery awaits! Your contributions will be crucial in helping us achieve our current goals, but remember, the window of opportunity might close sooner than expected.

Earn Your Badge of Honor!

As a token of appreciation for all the contributions, we’re introducing badges for each app we launch! By simply participating and running tasks for any specific app, you will automatically earn a badge—symbolizing your hard work and contribution to that particular project. Whether you're a veteran or new to Minecraft@Home, these badges will serve as a lasting reminder of your involvement in our unique discoveries.

Note: Badges may not be implemented for each app immediately and do take at least 24 hrs to populate after you run an applicable task. Do not fret if you don't see it yet.


Current Apps Running on Minecraft@Home:

One of the exciting apps we're running is HDWGH SSG, short for "How Did We Get Here Set Seed Glitchless." This app is dedicated to filtering data to find the ideal seed for speedrunning Minecraft in the highly competitive category where players must obtain the rare advancement "How Did We Get Here." This advancement is considered one of the most complex to achieve in Minecraft, requiring a player to juggle multiple status effects simultaneously. With HDWGH SSG, we aim to uncover the perfect seed that will allow speedrunners to maximize their efficiency in completing this challenging category.

Another active project is Pano121, short for 1.21 Panorama. This app focuses on finding carver seeds, which represent a specific type of internal seed-state in Minecraft. These carver seeds are of particular interest because they match the iconic trial chamber scene shown in the background panorama of the 1.21 update. Minecraft players who love the art and atmosphere of the game's ever-changing panoramas will find this project especially intriguing, as we're searching for seeds that capture the exact features seen in one of Minecraft's latest visual showcases.

Join us now and help push the boundaries of Minecraft exploration! Don’t miss your chance to contribute while the work is still available.

Keep mining for knowledge,
The Minecraft@Home Team
12 Sep 2024, 23:21:02 UTC · Discuss

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