"The researchers, from Macquarie University in Sydney, Australia, found
a way to break the SHA-1 algorithm in significantly fewer tries than
previously required. Although the hash function was previously believed
to withstand attempts numbering 263, the researchers have been able to whittle that down to 252, a number that puts practical attacks well within grasp of well-funded organizations.
Secure hashing algorithms are designed to reduce text or digital files
to a unique series of letters and numbers that is often compared to the
document's signature. The findings, which were published Wednesday here (PDF),
mean it's easier to create what cryptographers call collisions in
SHA-1, in which two different sources share the same the same output."
Read more: http://www.theregister.co.uk/2009/06/10/digital_signature_weakness/
The whitepaper: http://eprint.iacr.org/2009/259.pdf
