'MD5'에 해당되는 글 11건
- 역상 저항성(preimage resistance): 주어진 해시 값에 대해, 그 해시 값을 생성하는 입력값을 찾는 것이 계산상 어렵다. 즉, 제 1 역상 공격에 대해 안전해야 한다. 이 성질은 일방향함수와 연관되어 있다.
- 제 2 역상 저항성(second preimage resistance): 입력 값에 대해, 그 입력의 해시 값을 바꾸지 않으면서 입력을 변경하는 것이 계산상 어렵다.제 2 역상 공격에 대해 안전해야 한다.
- 충돌 저항성(collision resistance): 해시 충돌에 대해 안전해야 한다. 같은 해시 값을 생성하는 두 개의 입력값을 찾는 것이 계산상 어려워야 한다.
즉, 입력값과 해시 값에 대해서, 해시 값을 망가뜨리지 않으면서 입력값을 수정하는 공격에 대해 안전해야 한다. 이러한 성질을 가지는 해시 값은 원래 입력값을 의도적으로 손상시키지 않았는지에 대한 검증 장치로 사용할 수 있다.
암호화 해시 함수의 비교
다음은 널리 알려진 암호화 해시 함수 알고리즘의 목록이다. 이들 중에는 안전하지 않다는 것이 밝혀진 것도 있다.
출처 : 위키백과
“RainbowCrack uses time-memory tradeoff algorithm to crack hashes. It differs from the hash crackers that use brute force algorithm. RainbowCrack is a general propose implementation of Philippe Oechslin’s faster time-memory trade-off technique. It crack hashes with rainbow tables.”
Official change log for RainbowCrack 1.5:
- Support 64-bit Windows operating systems
- Support 32-bit Linux operating systems (x86 only)
- Support 64-bit Linux operating systems (x86_64 only)
- Support rainbow table file larger than 2 GB
Dowload RainbowCrack 1.5:
RainbowCrack 1.5 – rainbowcrack-1.5-win32.zip/rainbowcrack-1.5-win64.zip/rainbowcrack-1.5-linux32.zip/rainbowcrack-1.5-linux64.zip – http://project-rainbowcrack.com/index.htm#download
List of Rainbow Tables
This is the change log for JtR version 1.7.7:
- Added Intel AVX and AMD XOP instruction sets support for bitslice DES (with C compiler intrinsics). New make targets: linux-x86-64-avx, linux-x86-64-xop, linux-x86-avx, and linux-x86-xop (these require recent versions of GCC and GNU binutils).
- A “dummy” “format” is now supported (plaintext passwords encoded in hexadecimal and prefixed with “$dummy$”) – for faster testing and tuning of custom wordlists, rule sets, .chr files, and external modes on already known or artificial passwords, as well as for testing of future and modified versions of John itself.
- Apache “$apr1$” MD5-based password hashes are now supported along with the FreeBSD-style MD5-based crypt(3) hashes that were supported previously. Hashes of both of these types may be loaded for cracking simultaneously.
- The “–salts” option
threshold is now applied before removal of previously cracked hashes for
consistent behavior with interrupted and continued sessions. (Suggested by
The “Idle = Y” setting (which is the default) is now ignored for OpenMP-enabled hash types when the actual number of threads is greater than 1. (Unfortunately, it did not work right at least with GNU libgomp on Linux.)
- When a cracking session terminates or is interrupted, John will now warn the user if the cracked passwords printed to the terminal while cracking are potentially incomplete. It will advise the user to use the “–show” option to see the complete set of cracked passwords with proper post-processing.
- When loading hashes specified on a line on their own (feature introduced in 1.7.6), the loader will now ignore leading and trailing whitespace.
- Unless a hash type is forced from the command line, the loader will now print warnings about additional hash types seen in the input files (beyond the hash type autodetected initially).
- For use primarily by the jumbo patch (and later by future enhancements to the official versions as well), the loader now includes logic to warn the user of ambiguous hash encodings (e.g. LM vs. NTLM vs. raw-MD5, all of which may be represented as 32 hexadecimal characters) and of excessive partial hash collisions, which it works around (these are typically caused by an incomplete implementation of a new hash type).
- The “unique” and “unshadow” programs have been made significantly faster.
- “DateTime”, “Repeats”, “Subsets”, “AtLeast1-Simple”, “AtLeast1-Generic”, and “Policy” external mode samples have been added to the default john.conf.
- The self-tests have been enhanced to detect more kinds of program bugs.
- A few minor bug fixes and enhancements were made.
This version has been sponsered by Rapid7.
Download John the Ripper v1.7.7
출처 : PenTestIT