Javascript MD5 Question

[jm]

Hi, I have a string I want to put in MD5. I found a script that will
do that (there were several), but I couldn't find anything that
translated it on the other side. I don't think I understand what MD5,
SHA-1, etc. are for.

If for example I have base64 encoding of something, I can send it and
decode it on the other side. Of course, someone could just decode it
if they knew it was base64 (it's more of an ignorance type of
security.)

So what's MD5 (and others) for? Just passwords? Is it so I can send a
password to the other side and the MD5 "checksum" matches to what the
other side should have in its database? In other words, it's not about
decoding with MD5, like base64, but just checksums?

Thank you.

 

[RobG]

Hi, I have a string I want to put in MD5. I found a script that will
do that (there were several), but I couldn't find anything that
translated it on the other side. I don't think I understand what MD5,
SHA-1, etc. are for.

<URL: http://en.wikipedia.org/wiki/Md5 >

 

[Michael Winter]

Hi, I have a string I want to put in MD5. I found a script that will
do that (there were several), but I couldn't find anything that
translated it on the other side.

That's because there isn't anything.

I don't think I understand what MD5, SHA-1, etc. are for.

They are hash functions. <http://en.wikipedia.org/wiki/Hash_function>
Specifically the cryptographic variety, and are one-way (unlike encryption).

[snip]

Mike

 

[mwql]

yeah you are right, afaik md5 is used like you described. Also, it's
used for data validation. Often a md5sum is provided, for a linux
distro, to check that what you have downloaded is uncorrupted (by
checksumming the download and making sure both checksums are the same)

 

[TC]

yeah you are right, afaik md5 is used like you described. Also, it's
used for data validation. Often a md5sum is provided, for a linux
distro, to check that what you have downloaded is uncorrupted (by
checksumming the download and making sure both checksums are the same)

It's probably no longer safe for that purpose, due to recent advances.

For example, this site:
http://cryptography.hyperlink.cz/MD5_collisions.html has a program
with the following usage: pack3 file1 file2 file3 file4 file5 file6
This creates two exe files with the same MD5 checksum. However, the
first exe (when run) extracts files 1-3, whereas the second exe (when
run) extract files 4-6! Oops.

TC (MVP MSAccess)
http://tc2.atspace.com