the act of compression reduces the size of the file(s) being compressed by encoding information and eliminating statistical redundancy.

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28
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4answers
9k 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 ...
22
votes
3answers
13k 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
2
votes
3answers
109 views

Security of decompression tools

How safe is it to decompress untrusted files with unrar-free? With unzip? I'm using debian jessie. What steps can be taken to minimize the threat while extracting the file's contents?
79
votes
5answers
9k views

Can simply decompressing a JPEG image trigger an exploit?

The novel Daemon is frequently praised for being realistic in its portrayal rather than just mashing buzzwords. However, this struck me as unrealistic: Gragg's e-mail contained a poisoned JPEG of ...
4
votes
1answer
1k 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 ...
9
votes
4answers
2k 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 ...
3
votes
1answer
540 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 ...
1
vote
2answers
32 views

Can BREACH be thwarted by simply adding a sort of “salt” into the page being compressed?

Django supplies GZip middleware, but the docs issue a stark warning about BREACH, which I had, hitherto, forgotten about. The first thought I had was that I should be able modify the middleware to ...