Tag: problem

Problem with the collision system

So,I did the very basic tutorial for phaser 3, which is a platformer. Following along those lines, I made my own custom platform(Striped Wavy Platform) and a custom player sprite(Red Amoeba) but somehow the collision is not working between the platform and the player .. Below are my screenshots followed by the code. Initial state

Final state: the amoeba sunk to the bottom

<!doctype html> <html lang="en"> <head>     <meta charset="UTF-8" />     <title>Making your first Phaser 3 Game - Part 2</title>     <script src="//cdn.jsdelivr.net/npm/phaser@3.11.0/dist/phaser.js"</script>     <style type="text/css">         body {             margin: 0;         }     </style> </head> <body>  <script type="text/javascript">      var config = {         type: Phaser.AUTO,         width: 800,         height: 600,         physics: {                              //for physics system           default: 'arcade',           arcade: {             gravity: { x: 200,                       y: 300},             debug: false           }         },         scene: {             preload: preload,             create: create,             update: update         }     };      var level;     var player;      var game = new Phaser.Game(config);      function preload ()     {         this.load.image('amoeba', 'PlatformerJam/amoeba.png');         this.load.image('ground', 'PlatformerJam/level_ground.png');         this.load.image('air', 'PlatformerJam/air_particle.png');     }      function create ()     {       level = this.physics.add.staticGroup();       level.create(400,300,'ground');        player = this.physics.add.sprite(400,300,'amoeba');       player.setBounce(0.2);        player.setCollideWorldBounds(true);            this.physics.add.collider(level,player);       }      function update ()     {     }  </script>  </body> </html>

An authentication protocol to prevent phishing & solve the problem of password reuse?

When writing about best practices for authentication, I find that today’s best practices still leave gaping holes in security, specifically not solving the problem of password reuse by users – websites are currently sent the user’s input which means they could be storing it without them knowing. It also means that a user that is tricked into visiting a malicious site instantly gives away their credentials.

When I talk of passwords, I believe that any authentication key, whether it be generated via biometrics, a physical key or a password should be forced to use this protocol.

I have been unable to find any such protocols online for this purpose, the current idea would be something of the sort (I’m not a crypto expert, this is merely an example).

1) The LoginID is passed to the server, the server responds with a user-set reply to validate they are logging in at the genuine site. 2) The user’s browser is sent a cryptographic key linked to their account, when the user inputs their password, the browser first encrypts this key with the users password & then hashes it, before sending it to the server. The server should then follow best practices for password storage as currently advised.

In sumarry, what is needed: 1) A mechanism when authenticating that is clear to users that they are logging in at the correct location that they believe they are. 2) The website must never receive the user’s actual authentication key.

Why? I first thought of this when thinking about multifactor authentication and thinking it is rather a bad idea to transmit biometrics to anybody for any reason in plaintext, (over encrypted channels, it doesn’t matter), as we have seen all too many times websites not taking adequate security measures, it is not so easy to change ones fingerprint. Included must be some form of mechanism to ensure the user does not transmit credentials to the wrong site. Hence I reccomend the two-stage login, the user login ID (which should not be a username or an email, it should be private), is entered, upon entry the user is sent the prompt they set, this could be an image or text or both, this acts as a way of preventing simple phishing attacks which aim to clone sites. THis is necessary to prevent phishing attacks else malicious sites will still mimick genuine ones, or unattentive users will fall victim. (I reccomend that the browsers flag login inputs as ‘insecure’, informing the user will be sent in plaintext, if websites choose not to adhere to this standard).

Again this is just an example. It just seems that it is not all too complex or costly to implement what would be a real advantage to user security. It would eliminate the need for a password manager & make password breaches a minor inconvenience. And as said earlier, it adresses the pressing issue of biometrics.

Again I’m no crypto expert, this is just a simple example protocol.

I have attempted to find information on protocols for this purpose but have failed. I have seen some answers on stackexchange reccomending such a thing, but not a dedicated post. I apoligise if this is a duplicate, the search terms on this matter predictably throw up irrelevant posts.

How do I resolve a non-unique HD Identifier problem?

I use a HD with a caddy adapter for saving some files. macOS attributes a unique identifier for each external drive connected. But I needed to swap my adapter for the same disk, and now it’s not mounting because the identifier is not unique:

error USBMSC Identifier (non-unique) on console.

In the past, for the same problem, I deleted the drive label/id/something – I don’t remember now – on a folder, and my drive would mount normally again when I reconnected it.

Does anyone know what it is I would have done on the folder to correct these IDs in the past?

Additional Info:

  • The disk is recognized by macOS internet recovery > Disk Utility
  • If I put the drive and try to open Disk Utility on currently installed macOS, it hangs and doesn’t load.
  • the disk is showed at command diskutil list, but fails to mount using diskutil mountDisk -t Apple_HFS /dev/disk2 /Volumes/Home
  • If I change the drive name on Internet Recovery and connect it to the macOS installed, it’s recognized on the first time, but not on a second.

It’s purely a mistake with unique id, and I know it could be resolved by deleting this id or a label, but I wasn’t able to find the article with the solution I used previously. I cannot erase the disk because it has some important files, and the drive is working normally. The problem is in the system.

Effective Procedures and P vs NP Problem

If, suppose, P doesn’t equal NP. Implication of this statement is that there is no effective procedure to solve a hard problem; however there exists an acceptable solution S. I have following two explicit queries:

  1. If an effective procedure cannot be given which yields a solution, in what sense is the S actually a solution? Does this defy the formal definition of solution? I am assuming that an effective procedure is equivalent to a proof.

  2. If there is no effective procedure to arrive at an accepted solution, this implies that solution is not a syntactic consequence of problem. According to formal definition, syntactic consequence is equivalent to an effective procedure. If solution to a hard problem is not a syntactic consequence of problem, what is it?

Problem with video drivers?

Regards, I just installed Ubuntu 18.10. Now update all the dirvers and repositories besides adding one of Nvidia. The problem is generated once I select the most recent version of the driver (415 open source code) of my gpu (750ti) at the time of restart when it starts changing the OS start resolution (load the start screen, the one that says ubuntu with the loading dots) and after that a black screen appears with what looks like a check of some kind which marks that everything is correct but the load of the OS is stuck there and nothing happens.