topic Re: hash128(), hash160 & hash256 ? in QlikView

hash128(), hash160 & hash256 ?

Wed, 05 Jun 2013 14:45:58 GMT

Hi community,

What is hash function?

What are the advantages of hash functions ?

what are the difference between hash128(), hash160 & hash256?

in which scenario we can use ?

Thanks and Regards

Satti

Re: hash128(), hash160 & hash256 ?

alexandros17 — Wed, 05 Jun 2013 14:54:54 GMT

Hash function creates an internal representation of fields associated;

replaces the old logic of concatenate strings so previously we had

field1 & field2 ... & fieldn as myfield

now we can write autonumberhash128(field1, field2 ...) as myfield

The advantage is that everithing is left to the function, the code is internal, univoque and safe.

128, 160, 256 depends on the number of bytes involved so if you have a long list of field you need 256 ...

Hope it helps

Re: hash128(), hash160 & hash256 ?

Mon, 10 Jun 2013 17:30:07 GMT

could you provide an example App ?

Thanks

Satti

Re: hash128(), hash160 & hash256 ?

rustyfishbones — Mon, 10 Jun 2013 17:37:44 GMT

You can use HASH128() if you want to scramble text

so in the Script or even an Expression List Box you can use;

HASH128(Product) as ScrambledProduct

Try it

I have attached a sample app where I have created a List Box Epression to emphasize HASH128

Regards

Re: hash128(), hash160 & hash256 ?

uacg0009 — Fri, 18 Oct 2013 07:00:23 GMT

I have checked the attached file. And the hash128() is useful and that's what I want. But I have another question. Is

there have any ways to make it back to original data if we use the hash128() function?

Sorry for my poor English.

Thanks!

Re: hash128(), hash160 & hash256 ?

rustyfishbones — Fri, 18 Oct 2013 07:16:45 GMT

Yes, just remove the HASH(128)

like in the example qvw I posted earlier

Instead of HASH128(Alpha)

just say Alpha and the strings will revert to the original

Re: hash128(), hash160 & hash256 ?

uacg0009 — Fri, 18 Oct 2013 07:41:26 GMT

Thanks for your answer. But sorry for my previous presentation. Maybe it's not so clear to let you know what I want.

Let me make it clarify. I just want a way like hash128() or some other functions that I don't know to make the data

encrypted. And I also need a way to make it back. Do you have any ideas about the problem?

Thanks and Best Regards!

Re: hash128(), hash160 & hash256 ?

rustyfishbones — Fri, 18 Oct 2013 08:11:20 GMT

You can use the Scramble option in Qlikview.

However to revert back to the actual Data you will need to reload the script.

Go to Document properties, choose your Field and Click Scramble.

This will keep the field Data Scrambled until the Document is reloaded

Thats all I know

Re: hash128(), hash160 & hash256 ?

barryharmsen — Fri, 07 Mar 2014 20:48:09 GMT

Hashing is a one-way operation, so you cannot (theoretically) decode a hashed value.

Re: hash128(), hash160 & hash256 ?

Wed, 21 Jan 2015 06:38:04 GMT

when do we want to scramble? whats the use when reloading will unscramble it back?

Re: hash128(), hash160 & hash256 ?

rustyfishbones — Tue, 27 Jan 2015 18:20:33 GMT

You would want to scramble when demoing Data

Re: hash128(), hash160 & hash256 ?

maxgro — Tue, 27 Jan 2015 19:18:36 GMT

ther is a good discussion here

http://community.qlik.com/message/304652#304652

the last post has a link to an encrypt/decrypt example (it seems)