Implications Of The Recent Hash Function Attacks

An anonymous reader writes "Cryptography Research has issued a Q&A that explains the security implications of the hash function collision attacks recently announced at CRYPTO 2004. Apparently the consequences can be catastrophic for certain kinds of code signing and digital signatures, but MD5 sums for checking binaries are (mostly) OK. While the speculation that SHA-1 is about to fail seems to be overblown, updating the many legacy systems and protocols that rely on MD5 is going to be a massive undertaking."

Comments

Re:Idiot Question

[ponds]

In many situations any data inconsistancy can cause catastrophe. When distributing binaries it isn't that big of a deal, however there are other applications of hashing algorithms.

Think about forensics: Someone gets arrested, computer confiscated. The first thing that happens is a hash checksum is ran of the disk, then a disk image is made, then the image checksum is verified to make sure that it is the same as the original disk. If the checksum of the original disk ever changes, the evidence is useless. When there are collisions in the algorithm, the checksum cannot prove, beyond a reasonable doubt, that the data has not been tampered with. Especially when the hashing algorithm is ran on 20 or more gigabytes of data, which is the typical case in forensics.

yes, it does invalidate its use

[bani]

you don't have to generate specific malicious code in order to exploit md5.

merely creating pure trash would be sufficient, think of the case of BIOS or other firmware. create random garbage with the same md5 hash and voila, you've turned your victim's PC/laptop/celphone/pda/etc into a doorstop.

there are many other ways that md5 can be exploited, this is only one.