On August 17, 2004, Saint Barbala, California, was held (CRYPTO'2004) arranged three special reports on the mixed function. After the International Famous Cipher Eli Biham and Antoine Joux have made the analysis of SHA-1 and give a collision of SHA-0, Professor Wang Xiaoyun from Shandong University has done the MD5, HAVAL-128, MD4 and RIPEMD algorithms. Report. On the venue, when she announced the crack result of the MD series algorithm, the report was excited applause. Professor Wang Xiaoyun sensited the audience and got the admiration of participating experts. At the end of the report, the participants warmly applauded, some scholars were tribute, which was rare in the cryptographic meeting. Why did Wang Xiaoyun's report cause such a big response? Because her research results as a major discovery of the codenics, the fortress of the world password standard MD5, which is the world password standard MD5, which triggered the sylves of the cryptography. The conference summary report wrote this: "What should we do? MD5 is hit; it is about to eliminate it from the application. SHA-1 is still alive, but I have seen it on the end. Now I have to start replacement SHA-1." Keywords: collision = Vulnerability = others can fake and use digital signatures. Hash function and digital signature (digital handprint) haveh function, also known as a mixed function, a password algorithm for extensive and important applications in the field of information security, has a model similar to fingerprint. In the network security protocol, the mixed function is used to handle electronic signatures, compressing lengthy signature files into a unique digital information, ensuring the legality and security of the original digital signature file like fingerprint authentication. SHA-1 and MD5 mentioned earlier are the most commonly used mixed functions. After the processing of these algorithms, the original information will also become a complete "fingerprint" even if only one letter is only a letter. This guarantees the uniqueness of processing information. Provide digital authentication for e-commerce. Safe whiskers must meet two requirements during design:
