59

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, ...


58

Tor uses a routing method called Onion routing. Much like an onion, each message (the core of the onion) is covered with layers of encryption. image attribution Your message is encrypted several times before it leaves your device. Node A can only decrypt (peel) the layer A, under which it would see the address of the next node. After the packet reaches the ...


27

In a perfect world, you are right: there should be no point in keeping data encrypted in RAM. The OS should keep strong separation between processes, clear RAM when it is reallocated to another process, and, if the attack model allows for an attacker stealing the device afterwards and doing some harddisk analysis, encrypt the swap (or use no swap at all, ...


26

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 ...


25

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 ...


25

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 ...


22

To answer my own question: It seems that some systems are, or rather were indeed insecure, leaking environment information to other processes. A similar issue to the present one is raised on github by user 'mitchblank' for the 'mosh' application (mobile shell). The author writes: Background: in the process image argv[] and envp[] are stored in the same ...


19

PII by definition is any information that can be used on its own or with other information to identify, contact, or locate a single person, or to identify an individual in context. And to answer your question, image of signature is a sensitive PII as it can be used to identify a person. As base64 encoding only obfuscate the data, that also shall be ...


17

TOR uses the principle of onion routing. Let us say there are 3 TOR nodes A,B and C involved (selected randomly by client) and the message is m. We assume the corresponding public keys of these nodes to be Pa,Pb and Pc. The message is repeatedly encrypted by the client starting with the public key of the exit node (Pc) followed by Pb and in the end Pa (...


16

To a large extent, yes. See RFC 4880, section 5.1: for each recipient, there is a "Public-Key Encrypted Session Key Packet" which contains the recipient key ID. This key ID is a 32-bit value which is used as index in key servers; there are key ID collisions, so this is not an absolute, totally accurate indication of the recipient, but it still gives a lot of ...


16

It really depends on what you're trying to protect. SSL only protects data in transit, and between the two set points. It doesn't protect data at rest, and it doesn't offer any guarantee that the data came from the person claimed. So if you need to protect the data while it's stored at either of the endpoints, then encrypting it might make sense. Or if ...


15

Being able to process strings of arbitrary length without leaking information on their length seems to be very hard (i.e. I don't see how to do it) because of caches. A very long string, by definition, will take a lot of room, and thus reading the string will incur interaction with the caches. Accessing the string from RAM will trigger cache misses, and also ...


14

Why even store it in a MySQL database when you can be using Authorize.Net's Customer Information Manager API and taking PCI compliance and security issues right out of your hands completely and letting them do all of the heaving lifting for you? CIM let's you create customer payment profiles by storing the customer's credit card information on their end and ...


14

In a similar vein, but slightly different. Rather than using audio recordings this link shows that you can point a laser at the back of a laptop monitor and determine what is being typed based on the vibrations of the screen. Here is the original presentation slides


12

The key regulation you must follow is the Payment Card Industry Data Security Standard (PCI DSS) and of specific interest here is section 3.4 - Protect Stored Cardholder Data Render PAN unreadable anywhere it is stored (including on portable digital media, backup media, and in logs) by using any of the following approaches: One-way hashes based on ...


12

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 ...


12

This is far-fetched, but non-obvious information leaks: 1. We must keep empty drawers locked If someone knows that there is a regular meeting discussing secret project X every Tuesday and Friday; and noticed that the drawers are always empty and unlocked on Tuesday and Friday, but locked otherwise, then it's pretty clear indication that the content of ...


11

Yes and no. The url is 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 ...


11

Theoretically yes. In practice, it is a bit complex for amateurs. In Older Times, when people used dialup modems, plugging on the line was just a matter of a pair of crocodile clips and hooking another modem, tuned to be "receive only". Nowadays, people use ADSL, coaxial cable or optic fiber, and the much higher data rates mean that inexpert plugging will ...


11

Your question is difficult to answer because security is a property of a system, not a property of a single technology or algorithm. Confidentiality It can be assured using encryption, but that's not enough. You need to look at the whole system to give a meaningful answer. Here's a system that uses encryption and doesn't guarantee confidentiality: The WEP ...


10

None that I know of. And I believe this is because.. I don't think the solution (implied by the question) is a good solution/proposal. Not only because hashing function may have collisions (even if it has a very low probability, the impact would be major, so why should we add such a risk ?) but also because you have another problem prior to hashing: unless ...


10

Keeping information in RAM can enhance security, if done right and if the requirements allow it. I'm going to show two security architectures where keeping the data in RAM provides a security benefit. These are fairly specific scenarios; most of the time keeping data in RAM doesn't help. Protection against file dump attacks Consider a web application that ...


10

This is known as "Acoustic Keyboard Eavesdropping". In 2004 Dmitri Asonov and Rakesh Agrawal from IBM published a paper (pdf) that describes such an attack. The following is the abstract of that paper: We show that PC keyboards, notebook keyboards, telephone and ATM pads are vulnerable to attacks based on differentiating the sound emanated by ...


10

This is not very uncommon. Unfortunately you have no single solution, unless the individual is in the same locale as you (in which case you may be able to take legal action if he is causing you to incur costs) Generally, there is no technical solution, as this is a human problem. They could be doing it deliberately, as Pacerier suggests, or they may just ...


10

Yes, multiple layers of encryption using different algorithms and different keys make the encryption as hard as the hardest in the chain. IIRC this was adressed in Bruce Schneier's book Applied Cryptography (2nd edition). But the important part is to use different algorithms, or at least different keys. Algorithms that use "round keys" are often optimized ...


10

A replay attack is an attack where you record a legitimate transaction and then replay it at a later date. It is not an attack on confidentiality because the attacker isn't learning any new information: he has the same data than what he recorded in the first place. it might lead to an unauthorized access but that is a different issue. It is not an attack ...


9

TLS stacks are starting to send Server Name Indication (SNI, http://en.wikipedia.org/wiki/Server_Name_Indication; http://www.ietf.org/rfc/rfc3546.txt). That is sent in the clear, meaning eavesdroppers can see the server name you type into the address bar.


9

Going to have another go at this one, to try and address the many excellent comments... A cheque is an instruction to a bank to take money from Alice's account and give it to Bob. In order to act on it, the bank need to know Alice's account details; they must be written on the cheque in some form when it arrives for clearing. A pre-printed cheque in Alice'...


9

Rather than "bypass" encryption, they can spoof the identity of the server, so as to perform a MITM attack (effectively). Encryption itself is only one part of the configuration when setting up an SSL/TLS connection: this ensures the confidentiality of the communication between the client and the server. Before that, the client needs to verify the identity ...


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