Editing MD4 (section)

==Security==
Weaknesses in MD4 were demonstrated by Den Boer and Bosselaers in a paper published in 1991.<ref>{{cite journal |author=Bert den Boer, Antoon Bosselaers |year=1991 |title=An Attack on the Last Two Rounds of MD4 |url=http://dsns.csie.nctu.edu.tw/research/crypto/HTML/PDF/C91/194.PDF |url-status=dead |archive-url=https://web.archive.org/web/20030523231212/http://dsns.csie.nctu.edu.tw/research/crypto/HTML/PDF/C91/194.PDF |archive-date=2003-05-23 }}</ref> The first full-round MD4 [[collision attack]] was found by [[Hans Dobbertin]] in 1995, which took only seconds to carry out at that time.<ref>{{cite journal |author=Hans Dobbertin |date=1995-10-23 |title=Cryptanalysis of MD4 |journal=Journal of Cryptology |volume=11 |issue=4 |pages=253–271 |doi=10.1007/s001459900047 |s2cid=7462235 |doi-access=free }}</ref> In August 2004, [[Wang Xiaoyun|Wang]] et al. found a very efficient collision attack, alongside attacks on later hash function designs in the MD4/MD5/SHA-1/RIPEMD family. This result was improved later by Sasaki et al., and generating a collision is now as cheap as verifying it (a few microseconds).<ref name=sasaki-2007 />

In 2008, the [[preimage resistance]] of MD4 was also broken by Gaëtan Leurent, with a 2<sup>102</sup> attack.<ref>{{cite journal |author=Gaëtan Leurent |title=MD4 is Not One-Way |date=2008-02-10 |journal=Fast Software Encryption, 15th International Workshop, FSE 2008 |volume=5086 |pages=412-428 |series=Lecture Notes in Computer Science |publisher=Springer |doi=10.1007/978-3-540-71039-4_26 |url=https://iacr.org/archive/fse2008/50860419/50860419.pdf |archive-url=https://web.archive.org/web/20110611225208/https://www.di.ens.fr/~leurent/files/MD4_FSE08.pdf |archive-date=2011-06-11 }}</ref> In 2010 Guo et al published a 2<sup>99.7</sup> attack.<ref>{{Cite book|chapter-url=https://www.academia.edu/20987202|pages=56–75|last1=Guo|first1=Jian|last2=Ling|first2=San|last3=Rechberger|first3=Christian|last4=Wang|first4=Huaxiong|title=Advances in Cryptology - ASIACRYPT 2010 |chapter=Advanced Meet-in-the-Middle Preimage Attacks: First Results on Full Tiger, and Improved Results on MD4 and SHA-2 |series=Lecture Notes in Computer Science |year=2010 |volume=6477 |doi=10.1007/978-3-642-17373-8_4 |isbn=978-3-642-17372-1 |doi-access=free|hdl=10356/94168|hdl-access=free}}</ref>

In 2011, RFC 6150 stated that RFC 1320 (MD4) is '''historic''' (obsolete).