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4
votes
1answer
15 views

Is flushing of all caches on any context switch between mutually-distrusting processes the only way to prevent cache timing attacks?

This article demonstrates a devastating Javascript-based cache timing attack that allows for cross-VM tracking of mouse movements and other activities by web pages. Is the only way to prevent ...
0
votes
0answers
44 views

What is the difference between traffic co-relation attack and timing attack?(with relation to VPN or TOR)

Till what I have understood of timing attack is that I send 5Mb request and my VPN also sends a 5Mb request(the adversary present at both the ends i.e my ISP and VPN's end,hence the adversary finding ...
3
votes
0answers
43 views

Are there any C++ STL alternatives which is bulletproof against timing attack?

Just out of curiosity, I wonder if there are any packages of popular algorithm/data structures which are secure against timing attack. I think GNU libstdc++ std::string::compare(), std::unordered_map ...
3
votes
1answer
65 views

Can timing attacks over a webservice be eliminated by standardizing the time it takes to return a request?

For example, would this (pseudo)-code work? let t = timeRightNow() let message = stuffWhoseTimingCantBeLeaked() waitUntilTime(t+1 second) send message Or similar? That way the time that the message ...
1
vote
1answer
102 views

Covert, Overt, and side channels

I am really confused between the following three terms: Overt Channel. Covert Channel. Side-Channel. I feel frustrated! I've been searching about them to find a clear explanation but I keep ...
1
vote
1answer
62 views

Timing side-channel attack example

I understand that timing side-channel attack is a measurement of time taken to execute cryptographic algorithms. I'd like to see a simple example that explains how timing attack takes a place on any ...
2
votes
1answer
38 views

Cross-language primitives against string comparison timing attacks?

Related, not a duplicate: Timing Safe String Comparison - Avoiding Length Leak I know about cache misses, let's assume we fit in a cache line swimmingly. Thomas' excellent answer doesn't talk about ...
1
vote
1answer
24 views

Usefulness of Server's Work Load given Timing Attack Resistance of Responses

I've read articles in the past discussing the importance of having timing attack resistant responses for information where knowing the time for evaluation would leak information about the data being ...
36
votes
8answers
4k views

Should I worry about remote timing attacks on string comparison? [duplicate]

Say we have a Java web application which uses a shared secret to verify the identity of the client. The secret is stored on the server, and the client transmits the secret over SSL where it is ...
5
votes
2answers
125 views

When can you not use strcmp?

I've read that one shouldn't use strncmp(userSuppliedPassword,origPassword,sizeOfArray) (or String.equals in Java) since one can use a timing attack to guess the password. Rather, one should use a ...
3
votes
0answers
360 views

SQL security - ACID transactions and locking to prevent financial fraud (timing attack?) [closed]

I am trying to prevent something similar to this from happening: http://hackingdistributed.com/2014/04/06/another-one-bites-the-dust-flexcoin/ Basically the financial exchange was using non-ACID ...
14
votes
7answers
939 views

Mitigate timing attack threat against password recovery page

We recently had an external security review performed on a public-facing website we manage. They noted that on the "recover password page", there are different response times when providing existing ...
-3
votes
1answer
48 views

What threats involve in cache miss

What are the possible consequences of a cache miss? In other word, is it possible that a cache miss could cause a security threat? Thank you.
5
votes
2answers
407 views

Can I prevent timing attacks with random delays?

I read recently about profiling for valid user accounts with timing attacks, IE the application-under-attack takes a predictably different amount of time to process say a login on a non-existent user ...
6
votes
1answer
276 views

PHP bin2hex vulnerable to timing attack?

I've read in a few places[1][2][3] of the desire to make PHP's bin2hex constant time. In what scenarios would bin2hex be vulnerable to a timing attack? Is this below code for handling a CSRF token ...
-1
votes
1answer
112 views

Are there security implications to not installing the Leap Second patch on Red Hat systems? [closed]

What are Leap Seconds? A leap second is a second which is added to Coordinated Universal Time (UTC) in order to synchronize atomic clocks with astronomical time. The reason we have to add a second ...
7
votes
2answers
261 views

How to slow down program execution

I have a simple executable binary. It takes as input a user supplied string and compares it with a private string using strcmp. How can I slow down the execution of this program such that I can launch ...
4
votes
0answers
107 views

What is the state of the art in internet timing attacks? [closed]

What is the shortest timing difference resolved by a timing attack demonstrated over the internet (not just a LAN)? This paper from 2009 suggests 15µs. By how much has that number improved?
3
votes
2answers
108 views

Are string comparson timing attacks practical over public networks

Related are-there-any-working-proof-of-concept-string-comparison-timing-attacks I was looking at doing some encryption and hashing in PHP and came across this note Please be careful when ...
2
votes
3answers
2k views

Simple string comparisons not secure against timing attacks [duplicate]

As I learned in a comment for How to encrypt in PHP, properly?, I was told using a string comparison like the following in PHP is susceptible to timing attacks. So it should not be used to compare two ...
1
vote
3answers
165 views

Constant time compares when array sizes are not equal?

What is the preferred or recommended way to pursue contestant time compares when array lengths are not equal? Should we exit as early as possible? Something like: if (array1.size() != array2.size()) ...
12
votes
2answers
2k views

Timing attack against HMAC in authenticated encryption?

In an answer to another question of mine, it was noted that a class using standard string comparison functions when checking the HMAC in authenticated encryption would make the class vulnerable to ...
4
votes
1answer
118 views

Timing attacks in managed code

I have heard that running code in a managed language, e.g. Java in the JVM, is impossible to protect against timing attacks due to the JITing nature of most managed runtimes. In concept I can agree ...
0
votes
2answers
391 views

Timing-safe string comparison in high-level languages

I'm looking for a reliable solution to compare two strings without leaking their content through time differences. The length of the strings is not secret. The background is this: I'm implementing ...
0
votes
0answers
25 views

Length-constant password comparison in scrypt? [duplicate]

E.g.: XORing the candidate against stored then comparing against 0. Do I need to worry? (my question is much in the same style as this question: Does bcrypt compare the hashes in ...
7
votes
1answer
188 views

Deanonymizing users by introducing structured delays to the network?

Here is a scheme for deanonymizing a user that I've been thinking about, just out of curiosity. I tried searching for it but didn't find much. Does this technique have a name? Are there any papers or ...
0
votes
1answer
81 views

Timing Attacks in RSA

Considering the classic scenario of Eve trying to listen in to Alice and Bob's conversation, if Eve can intercept messages between Alice and Bob but with no access to their computers would Timing ...
4
votes
1answer
992 views

Are there any working proof-of-concept string comparison timing attacks?

I've tried to reproduce a string comparison timing oracle in two languages (Java and Python), but I'm not seeing any correlation in the timing based on the input into the comparison. Are there any ...
18
votes
5answers
2k views

Timing Safe String Comparison - Avoiding Length Leak

Let's say that we're building a generic timing-safe comparison function for general purpose use. Making it so that it is safe when both strings are equal length is pretty well known. However, what I'm ...
12
votes
2answers
828 views

How does SSH defend against keystroke-timing attacks?

This paper: https://www.usenix.org/legacy/events/sec01/full_papers/song/song.pdf Explains how SSH can be compromised by analyzing the timing of the keystrokes to guess what the user is typing. It's ...
8
votes
2answers
2k views

Does bcrypt compare the hashes in “length-constant” time?

I saw this function slowEquals() while reading Salted Password Hashing - Doing it Right, which uses a byte-level xor comparison to avoid timing attacks. I was wondering whether this is what Bcrypt ...
0
votes
1answer
88 views

How to specify a Snort rule connection duration?

Is it even possible to specify into a snort rule the duration of a connection? For example: in this format Hour, Minute, Second H, M, S = 0, 2, 1 If a connection that has the duration of 2 minutes ...
3
votes
1answer
213 views

What are security implications of enabling access to performance counters on ARM Cortex A9?

On an ARM Cortex A9 core, privileged instructions have to be executed so that unprivileged code can use performance counters. For instance with this GCC inline code, which would have to be run in a ...
6
votes
2answers
2k views

Is it reasonable to prevent timing attacks by using fixed processing time

I have systems that perform cryptographic operations within a SSL/TLS tunnel. My concern is that I may leak timing information when encrypting, decrypting, or hashing. Part 1 Is it a good idea to ...
8
votes
2answers
255 views

Can't explain data from side channel attack attempt

I found the comparison function below (slightly modified) from a crypto library I was using. I was curious about the potential vulnerability to side channel attacks. Specifically, the character ...
-2
votes
1answer
171 views

Why did I get unresponsive script when I start my system and open web browser? [closed]

The script on opening web broswersays Warning: Unresponsive Script A script on this page may be busy,or it may have stopped responding.You can stop the script now,or you can continue to see if the ...
22
votes
1answer
3k views

Timing attacks on password hashes

Timing attacks can have a devastating impact in scenarios where the secret is involved, often in cases where byte-wise array comparison is used. Now there are those that advertise using constant ...