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One recent notable achievement by Minecraft@Home was the discovery[0] of the start screen panorama seed which was seen from Beta 1.8 up to 1.12. Reverse engine

One recent notable achievement by Minecraft@Home was the discovery[0] of the start screen panorama seed which was seen from Beta 1.8 up to 1.12. Reverse engineering Minecraft seeds is an impressive feat given that the search space is so large. The finding of Pewdiepie's survival Minecraft world seed was achieved (without Minecraft@Home) despite him revealing his coordinates via F3 only twice in the entire series[1][2][3]. [0] https://www.reddit.com/r/Minecraft/comments/hthrmk/big_news_we_have_found_the_seed_of_minecrafts/ https://www.reddit.com/r/Minecraft/comments/hthrmk/big_news_... [1] https://youtube.com/watch?v=LE8ml2hZVZM https://youtube.com/watch?v=LE8ml2hZVZM [2] https://youtube.com/watch?v=MbAymA6OAa4 https://youtube.com/watch?v=MbAymA6OAa4 [3] https://youtube.com/watch?v=qWnTRNw4mDY https://youtube.com/watch?v=qWnTRNw4mDY

siraben 6y ago
I should also follow up with a technique that might be of interest to programmers. Some Minecraft blocks have textures that appear rotated in one of four ways. Turns out this rotation is pseudorandom, the rotation number is a result of seeding Java's rand.nextLong() with the (x,y,z) coordinate of that block.[0] This has been used for "malicious" purposes such as finding the location of a base from a single screenshot, which can lead to its destruction on anarchy servers. The author of the linked video used a CUDA search to find the location of a wall of netherrack. [0] https://youtube.com/watch?v=6__hO4cc1pA https://youtube.com/watch?v=6__hO4cc1pA
- Balgair 6y ago
  Aside: 2b2t is the most notable of MC anarchy servers. Whenever I read about it, I'm amazed at the machinations of the people that play there. It's kinda like reading Eve Online after action reports of their big battles. I've no inclination to play on 2b2t, but it's great reading all the same.
  - Nannooskeeska 6y ago
    I have the same feeling about Dwarf Fortress. I absolutely love reading DF stories (see [0]), but the couple times I tried to play I just couldn't get into it. [0] https://lparchive.org/Dwarf-Fortress-Boatmurdered/ https://lparchive.org/Dwarf-Fortress-Boatmurdered/
    - kiaulen 6y ago
      I'm with you. Also hopeful that the DF steam release comes with a slightly easier to use UI. If you want similarly hilarious stories, try rimworld.
  - sorahn 6y ago
    I'm curious about what the implications of some of these projects will be for 2b2t. Given that the seed is known, couldn't people start finding bases from screenshots using some of these clusters of 'rotations of textures 'tricks?
    - siraben 6y ago
      Yes, these techniques have been used to find bases and destroy them. Along with the texture rotation trick, there's also the position of bedrock whose distribution is fixed in every Minecraft world, so if you show exposed bedrock during a base tour you are at risk of leaking coordinates. Natural terrain is also another factor, so share enough images of the area surrounding the base and it can be leaked similarly. See https://www.youtube.com/watch?v=I7Jz9RMybfM https://www.youtube.com/watch?v=I7Jz9RMybfM
- hinkley 6y ago
  Shouldn't... I know that Minecraft lazily generates the world, so the RNG for an arbitrary location has to be deterministic otherwise you get a mess. Why isn't the RNG for tiles based on the world seed and the location? That's at least a billion times more search space, still deterministic.
giancarlostoro 6y ago
I never thought about cracking seeds but apparrently based on location and details of the terrain its not impossible: https://gitlab.com/taleden/MCeed-A https://gitlab.com/taleden/MCeed-A
- Qub3d 6y ago
  There is a really interesting ongoing project to find the seed used for the default world and server icons: Part 1: https://www.youtube.com/watch?v=lbR8ZY1Nsm8 https://www.youtube.com/watch?v=lbR8ZY1Nsm8 Part 2: https://www.youtube.com/watch?v=eC7f9tMslVE https://www.youtube.com/watch?v=eC7f9tMslVE Part 2 covers most of the efforts to reverse-engineer the seed.
  - giancarlostoro 6y ago
    This is quite fascinating, I hope they find it, I'm surprised they havent just emailed Mojang about it.
    - johanj 6y ago
      Part 2 of the videos mentions that Notch replied, saying that he doesn’t remember where the image is from, and that it’s likely coming from a world generated with a random seed.
    - sorahn 6y ago
      Dinnerbone has also commented on reddit threads saying they support the project, but they don't think there's anything else mojang can do to help.
gruez 6y ago
>One recent notable achievement by Minecraft@Home was the discovery[0] of the start screen panorama seed which was seen from Beta 1.8 up to 1.12. Can't this be done by reverse engineering the .jar files? You'd think that the start screen would be procedually generated from a seed (eg. rather than load_world_from_file("start_screen.map"), you'd do generate_world_from_seed("my seed"), because that's way easier than hard coding in the generated world.
- 7786655 6y ago
  The start screen is just an image with some distortion.

siraben 6y ago

I should also follow up with a technique that might be of interest to programmers. Some Minecraft blocks have textures that appear rotated in one of four ways. Turns out this rotation is pseudorandom, the rotation number is a result of seeding Java's rand.nextLong() with the (x,y,z) coordinate of that block.[0] This has been used for "malicious" purposes such as finding the location of a base from a single screenshot, which can lead to its destruction on anarchy servers. The author of the linked video used a CUDA search to find the location of a wall of netherrack. [0] https://youtube.com/watch?v=6__hO4cc1pA https://youtube.com/watch?v=6__hO4cc1pA

Balgair 6y ago
Aside: 2b2t is the most notable of MC anarchy servers. Whenever I read about it, I'm amazed at the machinations of the people that play there. It's kinda like reading Eve Online after action reports of their big battles. I've no inclination to play on 2b2t, but it's great reading all the same.
- Nannooskeeska 6y ago
  I have the same feeling about Dwarf Fortress. I absolutely love reading DF stories (see [0]), but the couple times I tried to play I just couldn't get into it. [0] https://lparchive.org/Dwarf-Fortress-Boatmurdered/ https://lparchive.org/Dwarf-Fortress-Boatmurdered/
  - kiaulen 6y ago
    I'm with you. Also hopeful that the DF steam release comes with a slightly easier to use UI. If you want similarly hilarious stories, try rimworld.
- sorahn 6y ago
  I'm curious about what the implications of some of these projects will be for 2b2t. Given that the seed is known, couldn't people start finding bases from screenshots using some of these clusters of 'rotations of textures 'tricks?
  - siraben 6y ago
    Yes, these techniques have been used to find bases and destroy them. Along with the texture rotation trick, there's also the position of bedrock whose distribution is fixed in every Minecraft world, so if you show exposed bedrock during a base tour you are at risk of leaking coordinates. Natural terrain is also another factor, so share enough images of the area surrounding the base and it can be leaked similarly. See https://www.youtube.com/watch?v=I7Jz9RMybfM https://www.youtube.com/watch?v=I7Jz9RMybfM
hinkley 6y ago
Shouldn't... I know that Minecraft lazily generates the world, so the RNG for an arbitrary location has to be deterministic otherwise you get a mess. Why isn't the RNG for tiles based on the world seed and the location? That's at least a billion times more search space, still deterministic.

giancarlostoro 6y ago

I never thought about cracking seeds but apparrently based on location and details of the terrain its not impossible: https://gitlab.com/taleden/MCeed-A https://gitlab.com/taleden/MCeed-A

Qub3d 6y ago
There is a really interesting ongoing project to find the seed used for the default world and server icons: Part 1: https://www.youtube.com/watch?v=lbR8ZY1Nsm8 https://www.youtube.com/watch?v=lbR8ZY1Nsm8 Part 2: https://www.youtube.com/watch?v=eC7f9tMslVE https://www.youtube.com/watch?v=eC7f9tMslVE Part 2 covers most of the efforts to reverse-engineer the seed.
- giancarlostoro 6y ago
  This is quite fascinating, I hope they find it, I'm surprised they havent just emailed Mojang about it.
  - johanj 6y ago
    Part 2 of the videos mentions that Notch replied, saying that he doesn’t remember where the image is from, and that it’s likely coming from a world generated with a random seed.
  - sorahn 6y ago
    Dinnerbone has also commented on reddit threads saying they support the project, but they don't think there's anything else mojang can do to help.

gruez 6y ago

>One recent notable achievement by Minecraft@Home was the discovery[0] of the start screen panorama seed which was seen from Beta 1.8 up to 1.12. Can't this be done by reverse engineering the .jar files? You'd think that the start screen would be procedually generated from a seed (eg. rather than load_world_from_file("start_screen.map"), you'd do generate_world_from_seed("my seed"), because that's way easier than hard coding in the generated world.

7786655 6y ago
The start screen is just an image with some distortion.