JH

1 The algorithm

Author(s): Hongjun Wu
Website: http://icsd.i2r.a-star.edu.sg/staff/hongjun/jh/
NIST submission package:
- round 1/2: JH_Round2.zip (old versions: JH.zip, JHUpdate.zip)

Hongjun Wu - The Hash Function JH

,2009

http://icsd.i2r.a-star.edu.sg/staff/hongjun/jh/jh_round2.pdf
Bibtex

Author : Hongjun Wu
Title : The Hash Function JH
In : -
Address :
Date : 2009

Hongjun Wu - The Hash Function JH

,2008

http://icsd.i2r.a-star.edu.sg/staff/hongjun/jh/jh.pdf
Bibtex

Author : Hongjun Wu
Title : The Hash Function JH
In : -
Address :
Date : 2008

2 Cryptanalysis

We distinguish between two cases: results on the complete hash function, and results on underlying building blocks.

A description of the tables is given here.

Recommended security parameter: 35.5 rounds

2.1 Hash function

Here we list results on the hash function according to the NIST requirements. The only allowed modification is to change the security parameter.

Type of Analysis	Hash Size (n)	Parameters	Compression Function Calls	Memory Requirements	Reference
preimage	512		2⁵⁰⁷	2⁵⁰⁷	Bhattacharyya et al.
preimage⁽¹⁾	512		2^510.3 (+ 2⁵²⁴ MA + 2⁵²⁴ CMP)	2^510.3 (Wu: 2^510.6)	Mendel,Thomsen, Wu

⁽¹⁾ Wu has analyzed the exact memory requirements, additional memory accesses (MA) and comparisons (CMP) of the attack by Mendel and Thomsen.

2.2 Building blocks

Here we list results on underlying building blocks, and the hash function modified by other means than the security parameter.

Note that these results assume more direct control or access over some internal variables (aka. free-start, pseudo, compression function, block cipher, or permutation attacks).

Type of Analysis	Hash Function Part	Hash Size (n)	Parameters/Variants	Compression Function Calls	Memory Requirements	Reference
semi-free-start collision	hash	256	16 rounds	2^178.24	2^101.12	Rijmen,Toz,Varıcı
semi-free-start near collision	compression function	256	19 rounds	2^156.77	2^143.70	Rijmen,Toz,Varıcı
semi-free-start near collision	compression function	256	22 rounds	2^156.56	2^143.70	Rijmen,Toz,Varıcı
pseudo-collision	compression function	all		-	-	Bagheri
pseudo-2nd preimage	compression	all		-	-	Bagheri