Is there an algorithm that computes the strength of a digest alg? (original) (raw)

Xuelei Fan xuelei.fan at oracle.com
Mon Oct 24 03:24:47 UTC 2011

I don't think we have similar methods.

I was wondering, sometimes, we may not be able to compare the strength of two hash functions strictly. There are different "attacks" on different hash functions. One hash function maybe safe to one attack method but may be weak for another attack method.

In another case, before 2004 (SHA-1 is reported broken this year), we can say SHA-1 is "stronger" than "MD2". But now, we may not be able to say it any more, because it is a little easier (in complexity) to crack SHA-1 than MD2 according to some researchs.

Xuelei

On 10/24/2011 9:52 AM, Weijun Wang wrote:

Hi Andrew

I need a method boolean isWeakerThan(String a1, String a2) so that isWeakerThan("MD5", "SHA1") returns true and isWeakerThan("SHA-256", "SHA1") returns false. I know you have done a lot of constraints works in JDK 7. Do you have an existing one? Otherwise, I plan to manually assign a value to each known algorithm and compare it. Thanks Max

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