[Courses] [security] Crypto Scientists Crack Prime Problem

[Sujita Purushothaman]

Raven Alder wrote:
<snip>

>         In the real world, a common hashing algorithm is Ron Rivest's
> Message Digest algorithm MD5.  He's the R in RSA.  [grin]  It produces a
> hash with less chance of being able to change the message and get then
> same hash than my theoretical "add up the ASCII and divide by 17,000"
> does.  So the combination of MD5 hashing and public key infrastructure
> (PKI) allows digital signatures.  There are other, more complex ways to
> do the same thing with digital certificates.  But that's a whole other
> mail.  [grin]
>

Thank you so much. That long explanation cleared up a lot of confusion.
More questions.Hope you don't mind. Sometimes on the web we find some pages
that have been digitally 'signed' . That means some software on our computer
decrypts the  hash and also checks whether the hash matches ie. if RSA was
used
to encrypt the hash and MD5 for hashing , some software is capable of doing
RSA
decryption and MD5 'unhashing'. Is it the browser?Or am I totally wrong here?
And what is CA verification? I know it is some way of verifying that the
user's
digital certificate is valid. How does it work?

Thanks.
Rgds,
Sujita