Strange cheaper alternative to encoding

Discussion in 'Advanced Programming Discussion' started by Joe Ellis, Oct 5, 2019.

  1. Joe Ellis

    Joe Ellis Member

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    Today I discovered that if you write 2 specific bytes at the start of any file that it turns all the characters to chinese symbols when opened in a text editor like notepad or wordpad. (255, 254)

    I'm expecting it's something to do with character translation from binary, but I don't know why this happens at all.

    This is good for me, as the files my engine creates can easily be encoded with no lag instead of the entire buffer having to be encoded.
    I'm mainly wondering if anyone knows about this and most importantly if it's a bad idea to use this as a form of encoding
     
  2. IndianaBones

    IndianaBones Member

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    If you haven't found the answer already, here's what I discovered. Knowing that 255, 254 in Hex is 0xFFFE, I googled around a bit which revealed that if using these characters at the start of a text file, indicates that the files byte order is little-endian.

    See here : https://en.wikipedia.org/wiki/Endianness

     
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  3. Joe Ellis

    Joe Ellis Member

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    Cool, that's the kind of thing I was imagining. As it stands, I think this is as effective as any encoding option, basically making it unreadable in notepad- stopping casual editing
     
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  4. Lord KJWilliams

    Lord KJWilliams Member

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    If you want to encode your text files, write them backwards as a binary file and read them backwards to translate them back into a text file. This means the first byte in your binary file will be the EOF of your text file, and the last byte of your binary file is actually the first byte of your text file originally. The part of the program that reads the file, reads the bytes backwards in binary from the last byte to the first byte, to translate into a text file. After the translation, you can use the text file that was derived from the binary file. The same coding method to write backwards, is also used to read backwards since it goes to the EOF byte position of the file.

    "0\l\r\ !dlroW olleH"

    Late Edit : I meant to use the word encryption, not encoding ( which I confused in my train of thought )
     
    Last edited: Oct 8, 2019
  5. TsukaYuriko

    TsukaYuriko Q&A Spawn Camper Forum Staff Moderator

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    Are we talking about encryption here? If so, the presented approach is not suitable for your target application. It is not by any means encryption. It is also conceptually different from encoding. Encoding attempts to ensure data is readable, while encryption intends to prevent it, at least for prying eyes.

    You may think you're encrypting the data, but you're really just (accidentally!) instructing common text processing software to display the (unchanged) data a certain way - or, in other words, messing up the encoding. It's a bit like opening an image in a text editor and concluding that because you can't see an image, people won't be able to steal your graphics. Actual encryption involves changing the data, not the display of said data, and actually offers security to a certain extent. Open one "encrypted" (or not so encrypted) file you created this way and manually change the encoding (actually encoding) to the proper one, and you'll see exactly what you put there... some strange characters at the start, followed by the original data.
     
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  6. Joe Ellis

    Joe Ellis Member

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    I don't know why you think I'm talking about encrytion, I've said encoding throughout the whole thread. I know that this method doesn't make it unopenable or uneditable, but the point was that it makes it unreadable in a text editor just like any encoding method and it's just as easy for someone to make a small program that removes the first 2 bytes as it is to decode from base64. but the difference with this is that it doesn't cause any lag cus it doesn't have to process the entire file.
    So my point is still correct that it is an effective alternative to encoding

    I'm practically going off what the manual says about encoding: https://docs2.yoyogames.com/source/_build/3_scripting/4_gml_reference/file handling/index.html

    So you can't really blame me if it's wrong
     
    Last edited: Oct 8, 2019
  7. FrostyCat

    FrostyCat Member

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    People who can't tell the difference between encoding and encrypting should not offer advice on cryptography. Mangling the BOM won't stop someone with a hex editor or a text editor that supports encoding overrides (e.g. Notepad++).
     
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  8. Joe Ellis

    Joe Ellis Member

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    But I can tell the difference, nor am I offering advice on cryptography. I don't understand why people are misinterpreting what I'm saying
     
  9. Lord KJWilliams

    Lord KJWilliams Member

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    @Joe Ellis IMHO, your confusing the idea of encoding with the idea of encryption. Its very easy to confuse the two concepts. What your describing is encryption in your posts, if your intentions are that you dont want people to read your text files. Encoding is the method of how the data is written to be read later. For instance, ASCII (7-bit) and EBCDIC (8-bit) use two different methods for encoding text so that they can be read, but they're not encrypted. However, encryption is a form of encoding, but not the other way around.
     
  10. Joe Ellis

    Joe Ellis Member

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    I understand what your saying, but I'm sure I'm not confusing the two things. I've known what the difference is for ages and made quite a few encryption methods. But people do use encoding to make things unreadable too, its just that the encoding algorithms are easily reversible and supposed to be like that, and this thing I'm talking about is aswell

    It's mainly for aesthetics, not security
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    Looks better than
    shd_default Lofty Castle Default Settings Background Color Color 29, 70, 90 Cell Size Range 25, 1, 5000 Collision Radius Range 1, 1, 60000 View Radius Range 2000, 1, 60000 Point Radius Range 500, 1, 5000 Anisotropic Bool true Filter Textures Bool true Filter Sprites Bool false Alpha Test Ref Range 128, 0, 255 Global Uniforms Sun Direction Yawpitch 60, 60, 1 Sun Color Rgb 255, 255, 255 Ambient Color Rgb 38, 37, 46 Fog Color Rgb 0, 0, 0 Fog Start Range 300, 0, 1000000 Fog Length Range 4000, 0, 1000000 Fog Alpha Range 1, 0, 1 Instance obj_default General Object Index Object obj_default Model Model Lofty Castle Animation Hidden Frame Index Hidden Frame Speed Hidden Active Bool true Visible Bool true X Pos Real 0 Y Pos Real 0 Z Pos Real 0 Yaw Real 0 Pitch Real 0 Roll Real 0 Scale Real 1.00 Mask Mode Gl List mask_modes[4] Variables Instance obj_player_platformer General Object Index Object obj_player_platformer Model Model Default Animation Hidden Frame Index Hidden Frame Speed Hidden Active Bool true Visible Bool true X Pos Real -2450 Y Pos Real 2600 Z Pos Real 250 Yaw Real 0 Pitch Real 0 Roll Real 0 Scale Real 0.25 Mask Mode Gl List mask_modes[2] Radius Range 12.50, 1, 10000 Variables step_event Script player_platformer_step move_speed Real 7 accel Real 0.05 decel Real 0.15 grav Real 0.20 jump_spd Real 5.00 turn_spd Real 6 max_zspeed Real 30 turn_smooth Range 0.1, 0.01, 1 hp Real 100 max_health Real 100 armour Real 100 max_armour Real 100 camera_zoom Real 221 camera_z_pos Real 73
     
  11. GMWolf

    GMWolf aka fel666

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    Reading / writing from a file is going to be slower than whatever transformation you do with it.
    I would recommend you use base64 encoding if all you want is to stop people from just opening with a text editor, but don't care about real security.

    If you want performance, then write it in chunks, convert a chunk to base64, the async write it to the buffer, in a loop.



    But remember, if it's something the users may like to edit, but you don't care about doing full encryption, then leave it as plain text and let them modify it easily!
     
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  12. Joe Ellis

    Joe Ellis Member

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    My files are written with a buffer, a mix of binary values(u8, u16, u32 and f32) and strings for variable names and stuff, so they're not really editable in a text editor anyway. So I just wanted to make all of it unreadable cus it looks better than a bunch of non-letters and words mixed together.

    But if I can encode it using base_64 to to achieve this, or just write a 2 byte bom at the start, I'd rather do the second cus the saving and loading time
    will be much less.

    Anyway, all the source code the engine uses for loading and saving the different files is available for people to use, in the project(warp3d)
    So, I'm not bothered about the files being editable, in fact I'd be glad if people made programs that can edit them, similar to fbx, obj etc.
    And having encryption with every file would completely ruin people being able to share files(levels and models) with eachother.

    The only time I'm concerned with encryption is for when someone has completed a game and wants all the files to be encrypted, so I'm thinking of making a separate tool that encrypts them with a certain key, and the key would have to be written somewhere in the project's gml code and compiled into the exe. I'm guessing this still wouldn't be that hard for a hacker to retrieve, especially if they had access to the source code. But I don't really know how important this would be to most developers anyway, cus every game ends up being hacked if someone really wants to get into it.
    But I'm definitely gonna be working on the best encryption method I can think of, but that has nothing to do with this thread lol


    Also, I thought of a way to rephrase what I said at first to hopefully make it as straightforward as possible:

    Some people would want to encode a buffer before saving it so all the strings in it aren't readable by the human eye.
    But doing this will slow down the saving and loading process, especially when decoding it back when loading.
    So instead, they can just set a byte order marker at the start of the file.
    It achieves the same goal of the strings not being readable by the human eye, but is a heck of alot faster, and they don't have to decode it back when loading, just ignore the first 2 bytes.

    I also want to state that this method is even less secure than using base_64, so it's purely for the way a file looks when opened in notepad :)
     
  13. TsukaYuriko

    TsukaYuriko Q&A Spawn Camper Forum Staff Moderator

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    I assumed you're talking about encryption because the end result of encryption (dissuading people from reading or editing the data) seemed to be the effect you're going for, and because the immediately noticeable effect of messing up the BOM sort of looks like the data is encrypted, so I figured you may have mistaken it to be that. If that's not the case, apologies for jumping to conclusions.

    So let's try that once again, but this time going fully with encoding:

    You are correct that encoding tends to make data unreadable, or at least not readable as easily as the original data. The form of "encoding" you're presenting is not encoding data per se, though, as the original data is left intact, but rather messing up the byte-order mark (BOM) that indicates the endianness of the data following it. The BOM being present at all also implies that the encoding is Unicode, which is why the data ends up being displayed as mojibake (as you're now reading two bytes per character instead of one).

    In other words, you're changing the "use this encoding and endianness by default" setting. This causes text editors (that are aware of it) to misrepresent the data, as it is being read the wrong way as a result.


    What I meant regarding it not being suitable for the purpose of making it harder to read is that it's really just a matter of how a program reads the data.
    If the text editor you're using is not aware of Unicode or endianness, the effect of doing what you're describing is void.
    That aside, reversing the "encoding" is as simple as opening the file with UTF-8 encoding. You can also open it in a hex editor, where everything past the first two bytes will look as it always did.

    To summarize: Yes, you're making it look like garbage when opened via the default "open in Notepad". But that's about it, as it won't stop anyone who has ever used a hex editor from realizing it's still plain text.
     
  14. Yal

    Yal GMC Memer GMC Elder

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    This is trivially easy to reverse... a lot of programs aren't Unicode-aware, and Notepad is so simple it shouldn't be, it's just pretending it understands it.
    upload_2019-10-10_0-23-4.png

    A lot of programs can analyze file contents more thoroughly, and they'll see through your ruse.
     
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