Xanda's Blog !~!

Java Decompiler – Yet Another Fast Java Decompiler

Feb
09

I’ve heard about decompiling java class since 2007 (when I was in MIMOS) but never try it before. Maybe because I don’t really code in Java.. and I don’t really like Java 😛

But today, I’ve found something interesting to play with.. J2ME based one time password application.. Since I’m on Mac, so I’ve found that Java Decompiler (JD) is the most suitable tool to use for me..

Its also available for Windows and Linux..

See some screenshots HERE

Trusting Blowfish and Bruce Schneier is risky business

Aug
19

In last night’s episode of Fox’s thriller show, 24, there is a reference to the Blowfish algorithm which was designed by Bruce Schneier. On the show, an email message that contains the expected location of Jack Bauer is encrypted using Blowfish. The FBI intercepts the message and must decrypt it if they are to find him. I was curious to see what the 24 writers had up their sleeve. The answer: the designer of Blowfish put in a back door which was known to a former CTU operative. The FBI had leverage over the former CTU man because his wife was being held and faced at least 15 years in prison. The cipher was broken in seconds. Thanks a lot, Bruce! Thanks to your back door, Bauer is now being chased as a wanted man … at least until next week.

[Source: Avi Rubin]

RainbowCrack 1.4 is released

Jul
23

This version focus on more effective rainbow table file format. New features:

  • New compact rainbow table file format (.rtc) reduce rainbow table size by 50% to 56.25%
  • New rt2rtc utility convert rainbow table from raw file format (.rt) to compact file format (.rtc)
  • New rtc2rt utility convert rainbow table from compact file format (.rtc) to raw file format (.rt)
  • The rcrack/rcrack_cuda program support both .rt and .rtc rainbow table file format
  • Conversion from non-perfect to perfect rainbow table is supported by rt2rtc utility

Smaller rainbow table significantly improve table lookup performance!

Introduction
RainbowCrack is a general propose implementation of Philippe Oechslin’s faster time-memory trade-off technique. It cracks hashes with rainbow tables.

Features:

  • Full time-memory tradeoff tool suites, including rainbow table generation, sort, conversion and lookup
  • Support rainbow table of any hash algorithm
  • Support rainbow table of any charset
  • Support rainbow table in raw file format (.rt) and compact file format (.rtc)
  • Computation on multi-core processor support
  • Computation on GPU (via NVIDIA CUDA technology) support (not freely available)
  • Computation on multi-GPU (via NVIDIA CUDA technology) support (not freely available)
  • Runs on Windows XP 32-bit and Windows Vista 32-bit
  • Command line user interface

A brute force hash cracker generate all possible plaintexts and compute the corresponding hashes on the fly, and then compare the hashes with the target hash. The plaintext is found if one of them match, otherwise the intermediate computation results are discarded.

A time-memory tradeoff hash cracker need a precomputation stage, at the time all plaintext/hash pair within the selected hash algorithm, charset, plaintext length range are computed and the results are stored in files called rainbow table. It is time consuming to do this kind of computation. Once the one time precomputation is finished, hashes within the table can be cracked with much better performance than a brute force cracker.

Visit http://project-rainbowcrack.com/ for more information.

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