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6
votes
0answers
42 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?
2
votes
2answers
27 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
221 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 ...
0
votes
3answers
92 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()) ...
9
votes
2answers
960 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 ...
3
votes
1answer
76 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
196 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 ...
8
votes
1answer
178 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
61 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 ...
3
votes
1answer
607 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 ...
17
votes
5answers
1k 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 ...
11
votes
2answers
476 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 ...
6
votes
2answers
1k 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
72 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
175 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 ...
5
votes
2answers
1k 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
235 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
156 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 ...
17
votes
1answer
2k 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 ...