The tag has no wiki summary.

learn more… | top users | synonyms

33
votes
1answer
2k views

Does WinRAR leave traces of temporarily extracted files?

If I have an encrypted RAR file which will only open using a password, and I opened a file directly from within WinRAR by double clicking the file inside WinRAR, I assume that WinRAR will create a ...
24
votes
4answers
6k views

BREACH - a new attack against HTTP. What can be done?

Following on from CRIME, now we have BREACH to be presented at Black Hat in Las Vegas Thursday (today). From the linked article, it suggests that this attack against compression will not be as simple ...
15
votes
3answers
5k views

Encryption and compression of Data

If we want both encryption and compression during transmission then what will be the most preferable order. Encrypt then compress Compress then encrypt
6
votes
4answers
502 views

Is it safe for GPG to compress all messages prior to encryption by default?

By default, GPG compresses text during encryption. Additionally, RFC 4880 says: 2.3. Compression OpenPGP implementations SHOULD compress the message after applying the signature but before ...
5
votes
2answers
195 views

Zlib DEFLATE decompression bomb

Can you give me an example of a short data string that, when decompressed using Zlib's DEFLATE method, expands to something much much longer? More precisely: what is the nastiest decompression bomb ...
4
votes
1answer
827 views

Whats the best custom compression method to use when I have SSL?

Suppose I have an application which does encryption using SSL and provided you cannot control what cipher suite is being negotiated, and assuming that I have some custom compression over the data ...
3
votes
5answers
769 views

Does a binary executable have to have some critical plain-text components?

When companies package binary executables, they are often encrypted, compressed, scrambled, and otherwise made so that your lazy hacker can't simply open the program up in Notepad++ and see the code. ...
3
votes
1answer
336 views

Can Exchange/OWA still compress static images and be immune to HTTP compression attacks?

Microsoft Exchange / OWA (Outlook Web Access) allows for three different types of compression (link for Ex2010) Compression setting Description High Compresses both static and ...
3
votes
1answer
401 views

With BREACH attack, is session-based CSRF token still secure?

This is something I haven't been able wrap my head around, if BREACH allow leaking of information, do we have to mask or generate CSRF token in a time-based or per-request fashion to make it more ...
2
votes
1answer
63 views

Does storing your files as single compressed archives compromise integrity?

Compressing your files as tar.gz or zip for storage or backup saves space and is faster than handling thousands of files. But it looks like small corruptions in the archive, for example because of ...
1
vote
2answers
56 views

How can I encrypt compressed data safely?

As mentioned in this particular answer, compressing data before encryption may lead to the CRIME attack, especially if the hacker has collected many similar versions of the transmitted data. Let's ...
1
vote
1answer
87 views

can you update a one-time pad, over one-time pad encryption (compressed)?

This might well be a silly question, but at the moment I've not thought of a reason it doesn't work. As I think is generally known, you should never re-use a one-time pad. But compression allows you ...
1
vote
2answers
202 views

How to defeat CRIME, BREACH, TIME etc… server side (without sacrificing compression)

I am writing full-stack server side software and I have been researching CRIME attacks and it's relation to SPDY header compression as I am implementing the server side codecs for it at the moment. ...
0
votes
0answers
42 views

Fixing compression oracle in GZIP library

What design change would you add to the GZIP algorithm so that it makes sure that compression oracle is not present anymore? This is assuming that both the INFLATE and DEFLATE endpoint designs can be ...
-1
votes
1answer
510 views

Is Opera spying on its users when traffic conpression is enabled?

Correct me if I misunderstand the following quoted paragraphs, but basically to compress something it must be decrypted first. This seems to be the claim of the article but I don't see this as true. ...