Avast4.5 versus Application's MD5

[system]

While trying to fathom why my Auto. Updater would not work in 4.1 and now 4.5 I just happened to check each
Application’s MD5 in my Kerio Firewall.

Every one of the Apps. I highlight to check out says,

‘ALL Checksums Ok’.

However the two belonging to Avast say,

‘MD5 of App. is not correct’

Can someone more Techie. please take a stab at why the above would be - I do not have a clue re. what MD5’s are, let alone why they are not correct only in the case of Avast

Regards.

[Eddy]

4.5 I just happened to check each Application's MD5 in my Kerio Firewall.

Avast doesn't do that. Likely it is Kerio who is checking. And it is correct that the MD5 is "not correct" when it comes to Avast, since Avast has changed. (updates)

I do not have a clue re. what MD5's are

MD5 is an algorithm that is used to verify data integrity through the creation of a 128-bit message digest from data input (which may be a message of any length) that is claimed to be as unique to that specific data as a fingerprint is to the specific individual. MD5, which was developed by Professor Ronald L. Rivest of MIT, is intended for use with digital signature applications, which require that large files must be compressed by a secure method before being encrypted with a secret key, under a public key cryptosystem. MD5 is currently a standard, Internet Engineering Task Force (IETF) Request for Comments (RFC) 1321. According to the standard, it is "computationally infeasible" that any two messages that have been input to the MD5 algorithm could have as the output the same message digest, or that a false message could be created through apprehension of the message digest. MD5 is the third message digest algorithm created by Rivest. All three (the others are MD2 and MD4) have similar structures, but MD2 was optimized for 8-bit machines, in comparison with the two later formulas, which are optimized for 32-bit machines. The MD5 algorithm is an extension of MD4, which the critical review found to be fast, but possibly not absolutely secure. In comparison, MD5 is not quite as fast as the MD4 algorithm, but offers much more assurance of data security.

[igor0]

@Eddy

According to the standard, it is “computationally infeasible” that any two messages that have been input to the MD5 algorithm could have as the output the same message digest, or that a false message could be created through apprehension of the message digest.
…
In comparison, MD5 is not quite as fast as the MD4 algorithm, but offers much more assurance of data security.

Actually, it’s not fully true anymore. Recently, a few cryptologists discovered new attacks and have been able to generate MD5 (and other) collisions. MD5 is not considered to be “secure” for some time. However, for file version verification, it’s more then enough I’d say.

[system]

@Eddy

4.5 I just happened to check each Application's MD5 in my Kerio Firewall.

Avast doesn't do that. Likely it is Kerio who is checking. And it is correct that the MD5 is "not correct" when it comes to Avast, since Avast has changed. (updates)

Thanks again Eddy, I took a Pic. of the info. for learning. and to igor for the additional.

With that knowledge,( that Kerio initially gave permission for Avast to update - but then UNLIKE all my other programs Avast suddenly wants to CHANGE the rules in midstream and so Kerio pulls the plug on Avast) can you
think of how I now overcome that definite block please ?

Regards.

[system]

Eddy,
I’m sorry about the errors in my previous post - it’s too early, and shows that it’s not the time that one get’s up, but rather the time that one wakes up !

I hope that you could see my question, even though I kiboshed it ?

Regards.