Posts tagged: Encryption

Jun 26 2012

Crack RSA SecurID 800 Secret Key in 13 Minutes

RSA SecurID 800RSA’s SecurID 800 is one of at least five commercially available security devices susceptible to a new attack that extracts cryptographic keys used to log in to sensitive corporate and government networks.

Scientists have devised an attack that takes only minutes to steal the sensitive cryptographic keys stored on a raft of hardened security devices that corporations and government organizations use to access networks, encrypt hard drives, and digitally sign e-mails.

The exploit, described in a paper to be presented at the CRYPTO 2012 conference in August, requires just 13 minutes to extract a secret key from RSA’s SecurID 800, which company marketers hold out as a secure way for employees to store credentials needed to access confidential virtual private networks, corporate domains, and other sensitive environments. The attack also works against other widely used devices, including the electronic identification cards the government of Estonia requires all citizens 15 years or older to carry, as well as tokens made by a variety of other companies.

“They’re designed specifically to deal with the case where somebody gets physical access to it or takes control of a computer that has access to it, and they’re still supposed to hang onto their secrets and be secure,” Matthew Green, a professor specializing in cryptography in the computer science department at Johns Hopkins University, told Ars. “Here, if the malware is very smart, it can actually extract the keys out of the token. That’s why it’s dangerous.” Green has blogged about the attack here.

It’s this version of the attack the scientists used to extract secret keys stored on RSA’s SecurID 800 and many other devices that use PKCS#11, a programming interface included in a wide variety of commercial cryptographic devices. Under the attack Bleichenbacher devised, it took attackers about 215,000 oracle calls on average to pierce a 1024-bit cryptographic wrapper. That required enough overhead to prevent the attack from posing a practical threat against such devices. By modifying the algorithm used in the original attack, the revised method reduced the number of calls to just 9,400, requiring only about 13 minutes of queries, Green said.

Other devices that store RSA keys that are vulnerable to the same attack include the Aladdin eTokenPro and iKey 2032 made by SafeNet, the CyberFlex manufactured by Gemalto, and Siemens’ CardOS, according to the paper.

Nov 30 2011

BozoCrack – MD5 Password Hash Cracker

BozoCrack is a depressingly effective MD5 password hash cracker with almost zero CPU/GPU load. Instead of rainbow tables, dictionaries, or brute force, BozoCrack simply finds the plaintext password. Specifically, it googles the MD5 hash and hopes the plaintext appears somewhere on the first page of results.

It works way better than it ever should.

How?
Basic usage:

$ ruby bozocrack.rb my_md5_hashes.txt

The input file has no specified format. BozoCrack automatically picks up strings that look like MD5 hashes. A single line shouldn’t contain more than one hash.

Example with output:

$ ruby bozocrack.rb example.txt
Loaded 5 unique hashes
fcf1eed8596699624167416a1e7e122e:octopus
bed128365216c019988915ed3add75fb:passw0rd
d0763edaa9d9bd2a9516280e9044d885:monkey
dfd8c10c1b9b58c8bf102225ae3be9eb:12081977
ede6b50e7b5826fe48fc1f0fe772c48f:1q2w3e4r5t6y

Why?
To show just how bad an idea it is to use plain MD5 as a password hashing mechanism. Honestly, if the passwords can be cracked with this software, there are no excuses.

Who?
BozoCrack was written by Juuso Salonen

Download: bozocrack.rb

Jan 08 2010

768-bit RSA Cracked

Researchers have decomposed a 768-bit number with 232 decimal places into its two prime factors and published a paper with their results. The number is the string released as “RSA-768″ under the now defunct RSA Challenge. As a result, RSA encryptions with 768-bit keys must, from now on, be considered cracked.RSA Key

It took the team of researchers from Switzerland, Japan, Germany, France, the US and the Netherlands about two and a half years to perform the factorisation. The first step of the calculation, polynomial selection, required half a year on a cluster consisting of 80 PCs, while the second and considerably more labour-intensive sieving step took about two years on a cluster of several hundred computers. According to the researchers, a single Opteron processor with 2 Gbytes of RAM would have needed about 1,500 years to complete the sieving step.

As RSA-512 was cracked about a decade ago, the researchers assume that the computing power required to master RSA-1024 is likely to become available in about ten years. They therefore recommend that all 1024-bit RSA keys be decommissioned by 2014 at the latest.

Source: The H Security

Aug 28 2009

Cracking GSM phone crypto via distributed computing

If you are using a GSM phone (AT&T or T-Mobile in the U.S.), you likely have a few more months before it will be easy for practically anyone to spy on your communications.

Security researcher Karsten Nohl is launching an open-source, distributed computing project designed to crack the encryption used on GSM phones and compile it into a code book that can be used to decode conversations and any data that gets sent to and from the phone.

Karsten Nohl talks about his distributed computing, open-source AE/1 cracking project at the Hacking at Random conference.

“We’re not creating a vulnerability but publicizing a flaw that’s already being exploited very widely,” he said in a phone interview Monday.

This weakness in the encryption used on the phones, A5/1, has been known about for years. There are at least four commercial tools that allow for decrypting GSM communications that range in price from $100,000 to $250,000 depending on how fast you want the software to work, said Nohl, who previously has publicized weaknesses with wireless smart card chips used in transit systems.

It will take 80 high-performance computers about three months to do a brute force attack on A5/1 and create a large look-up table that will serve as the code book, said Nohl, who announced the project at the Hacking at Random conference in the Netherlands 10 days ago.

Using the code book, anyone could get the encryption key for any GSM call, SMS message, or other communication encrypted with A5/1 and listen to the call or read the data in the clear. If 160 people donate their computing resources to the project, it should only take one and a half months to complete, he said.

Participants download the software and three months later they share the files created with others, via BitTorrent, for instance, Nohl said. “We have no connection to them,” he added.

Once the look-up table is created it would be available for anyone to use.

Source: CNET News

Dec 03 2008

TrueCrypt – Free Open-Source Disk Encryption Software

TrueCrypt

TrueCrypt is a software system for establishing and maintaining an on-the-fly-encrypted volume (data storage device). On-the-fly encryption means that data are automatically encrypted or decrypted right before they are loaded or saved, without any user intervention. No data stored on an encrypted volume can be read (decrypted) without using the correct password/keyfile(s) or correct encryption keys. Entire file system is encrypted (e.g., file names, folder names, contents of every file, free space, meta data, etc).

Files can be copied to and from a mounted TrueCrypt volume just like they are copied to/from any normal disk (for example, by simple drag-and-drop operations). Files are automatically being decrypted on-the-fly (in memory/RAM) while they are being read or copied from an encrypted TrueCrypt volume. Similarly, files that are being written or copied to the TrueCrypt volume are automatically being encrypted on-the-fly (right before they are written to the disk) in RAM. Note that this does not mean that the whole file that is to be encrypted/decrypted must be stored in RAM before it can be encrypted/decrypted. There are no extra memory (RAM) requirements for TrueCrypt. For an illustration of how this is accomplished, see the following paragraph.

New features :
* Ability to encrypt a non-system partition without losing existing data on the partition. (Windows Vista/2008)Note: To encrypt a non-system partition in place, click ‘Create Volume‘ > ‘Encrypt a non-system partition‘ > ‘Standard volume‘ > ‘Select Device‘ > ‘Encrypt partition in place‘ and then follow the instructions in the wizard. Please note that this is not supported on Windows XP/2000/2003 as these versions of Windows do not natively support shrinking of a filesystem (the filesystem needs to be shrunk to make space for the volume header and backup header).
* Support for security tokens and smart cards (for more information, see section Security Tokens and Smart Cards in chapter Keyfiles).
* The TrueCrypt boot loader can be prevented from displaying any texts (by selecting Settings > System Encryption and enabling the option ‘Do not show any texts in the pre-boot authentication screen’).
* The TrueCrypt boot loader can now display a custom message (select Settings > System Encryption and enter the message in the corresponding field) either without any other texts or along with the standard TrueCrypt boot loader texts.
* Pre-boot authentication passwords can now be cached in the driver memory, which allows them to be used for mounting of non-system TrueCrypt volumes (select Settings > System Encryption and enable the option ‘Cache pre-boot authentication password‘).
* Linux and Mac OS X versions: The ability to mount a Windows system partition encrypted by TrueCrypt and to mount a partition located on a Windows system drive that is fully encrypted by a Windows version of TrueCrypt.

Latest Stable Version – 6.1a

Download :
http://www.truecrypt.org/downloads.php