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24

Because HTTPS is not very well suited to securing downloads of large public files. For this use case, it's slow and not that useful. There are reasons for not using HTTPS well beyond incompetence or unawareness. HTTPS requires more resources on the server. Google mail got it down to a 1% overhead and a 2% bandwidth overhead, but this is for a very different ...


20

Compilation is a mostly one-way operation, and it is not deterministic, at least not in a robust way. You could recompile the source code and see if it yields the same binary. However, the exact binary can vary depending on a lot of parameters, including the compilation options and the exact version of the used compiler. Moreover, some compilers embed some ...


18

The HTTPS protocol is equivalent to using HTTP over an SSL or TLS connection (over TCP). Thus, first a TCP connection (on port 443) is opened to the server. This is usually enough to reveal the server's host name (i.e. www.mysite.com in your case) to the attacker. The IP address is directly observed, and: you usually did an unencrypted DNS query before, ...


15

It depends on whether you are talking about the concepts, the terminology, or the acronym. Concepts of confidentiality, integrity and availability of information have been used by war generals for quite some time; for instance, one can see Julius Caesar operating along these lines during the Gallic Wars and he was certainly not the first to grasp the ...


14

An SSL certificate protects users of your site from having their communications intercepted by a 3rd party. I think it is likely that when you say your site was hacked, this isn't what you're talking about. An SSL certificate does not validate the content of your site, nor does it prevent anyone from accessing it as intended or otherwise. Controls for these ...


13

The scenario you describe is very similar to the concept of "remote attestation". There has been a lot of research on this and there are two major results: You need a trust anchor, such as the TPM or a trusted system service, to securely measure your app and report the results to the server. Otherwise you can always build a simulator that generates the ...


13

As @Paŭlo Ebermann and @Jeff Ferland have told you, the GET request is encrypted under SSL and so is safe. However, don't forget that many web servers log GET requests and parameters, and any credentials or other sensitive information you send via GET could be written to a log somewhere. For that reason, you should use POST (which will also be encrypted ...


12

I think there's something to be said for setting a bar, regardless of how low it is. Can Tripwire be bypassed? Sure. Will it catch things that you wouldn't otherwise? Yes it will. The main problem I've seen in a Tripwire installation is tuning it to where it isn't false-positive laden to the point of ignoring it. If it blows up every time someone ...


10

It's the same reason as why not all login prompts are using https yet: people are too lazy, think a certificate is too expensive, or have hosting that charges more for using https. The real question is why downloads are served over a plain connection more often than login forms. And I think this is mostly because of unawareness. Checksums are often ...


8

Tripwires are very useful for defending against userland rootkits. Kernelland rookits do not need to replace binaries to subvert the behavior of the system, usually these rootkits are just a Linux Kernel Module (LKM). In fact when you control the kernel like this any executable's behavior can be influenced without needing to modify the binary its self. ...


8

You should assume that the URL is not protected, i.e., that a passive eavesdropper may be able to learn what URL you are visiting. I realize this contradicts what some other folks are claiming, so I'd better explain. It is true that everything after the domain name is sent encrypted. For instance, if the url is https://www.example.com/foo/bar.html, then ...


8

BitTorrent uses a method called Chucking, in which files are divided into 64KB-2MB pieces and each piece is further divided into 8KB-32KB chunks. Each chunk is hashed and the hashes (along the chunking information) are stored in the torrent's metadata (the small .torrent file, or the metadata you receive via DHT). That, along with the info_hash, makes ...


8

Since injection attacks exploit control sequences in the way the output is interpreted, and since different output formats use different control sequences (think JavaScript versus SQL versus HTML), your sanitization technique needs to reflect where the output is going. If you sanitize for output upon input, you're making an assumption about where that output ...


7

Mozilla downloads are always signed. On Windows you right-click the downloaded file and go to the "Digital signatures" tab. There you can see the signature (should be "Mozilla Corporation") and whether it is valid. When you try to execute this file after downloading it from the web you will get a warning anyway and you will see the signature there as well. ...


7

If you have no liability for what the users do with the laptop, then what is the benefit to you of monitoring the usage. In the absence of any legitimate benefit, that would leave anyone questioning your motives in doing so - so you would create liability by doing this. There are a lot of other security concerns you should be concerned about - primarily ...


7

You can sign the data, but this leaves the problem that the private key needs to be embedded into the application in order to verify it. You can store the replay data on a server and allow the friends to access it using their own device. For an average game, it is likely not worth the effort because the data can already be manipulated at the time it is ...


7

SSL is "tamper-proof" in the following sense: no third party may alter the transferred data in any way, without the receiver being made aware of the tampering. Of course, an attacker can always cut the cables, disrupting communications ! But no alteration goes unnoticed, thanks to the use of Message Authentication Codes by SSL. Note that SSLv2 did not ...


7

The MD5 hash algorithm has been demonstrated to be weak to collision attacks. This means that an attacker can generate two files which will produce the same hash value. This has no bearing on file integrity checks. To create a file that matches a previously known hash, the algorithm has to be weak against second preimage attacks. While MD5 has some ...


6

SSL certificates don't do anything to prevent your site from being hacked, so you're not going to be able to claim compensation. If properly implemented, they prevent your users' traffic from being intercepted by third parties, which is not the same thing at all. To stop your site from being hacked again, you need to employ or become an expert in Internet ...


6

What are the flaws in this scenario? The basic flaw here is that you are assuming that the remote party is adhering to your rules. You have a server with a program. You receive a download request. At this point you have no idea who or what the remote downloader is. Once downloaded, an adversary can save it wherever they please. They can attempt ...


6

Regarding extension: The scheme you propose is also easy to break: I record the hash that your software sends to the server, then modify the app and reply the hash whenever the server asks for it. Even if you make a challenge-response-style protocol(to provide freshness), I can debug your app to find out how you generate the response. This attack is in ...


6

You can make it harder for an attacker to modify the files, but you cannot prevent modification of anything you give away to the attacker in the end. That is assuming the attacker has full access to his computer. There is some work being done by the Trusted Computing Group and other vendors to restrict the abilities of the owner. Those trusting computing ...


6

I suspect you are slightly confused about how Bell-Lapadula works, and in particular, how categories work in Bell-Lapadula. Classifications are necessarily ordered. In your example, we have Restricted < Confidential < Secret < Top Secret. So far, so good. Categories are, in general, not ordered. Often, they are a set, with no ordering amongst ...


6

The following things will leak before your session starts: IP Address of the server Certificate of the server That will include the domain name published on the certificate, though that doesn't guarantee it will match what you used. You DNS queries No data or requests that aren't related to creating the SSL connection (GET ...) are sent to the server ...


6

Yes and no. The url in encrypted properly, so query parameters should never be revealed directly. However, traffic analysis can get the length of the URL often - and knowing the server and the length of the url is often enough to eavesdrop what pages are being accessed, especially if assuming that links on a page are clicked. Google for "traffic analysis ...


6

This is exactly the problem that Secure Boot was created to solve. The problem is that if you don't have a chain of trust going all the way back to POST, then you can't guarantee that there hasn't been tampering. (And even then, "guarantee" is an exaggeration). You can checksum the boot partition at startup; perhaps use the checksum as part of the key for ...


6

SSL/TLS is designed to be tamper proof, as described in the introduction of the specification: The primary goal of the TLS Protocol is to provide privacy and data integrity between two communicating applications. [...] - The connection is reliable. Message transport includes a message integrity check using a keyed MAC. Secure hash ...


5

[Restricted, Confidential, Secret, Top Secret] => [0, 1, 2, 3] //constants [Lieutenant, Colonel, Captain, Lieutenant General, General] => [0, 1, 2, 3, 4] //constants Set this up in a static class similar to how Math.MAX_INT and others work ... Classification.RESTRICTED will return 0. That makes it easy to read from a programmer's standpoint. How ...


5

Computers are so magic, that they seem disconnected from all social conventions and mundane realities. But that's just a "mirage". Let's translate your question by making just a small change: assume that you want to loan houses instead of laptops. Your question then becomes: I want to be able to enter the houses, to see if the tenant has any issue, or to ...



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