hash - Is there an issue with putting a longer input string to a hashing algorithm than the algorithm outputs? -


currently i'm designing hashing system user emails, happens if user email longer hash output. use sha1 sha256 or sha512 if makes difference based on algorithm... seems @ point algorithm wouldn't able keep on producing unique outputs.

hash values have fixed length 13 (des) 86 (sha2) characters. it's normal if give longer input. think of "cross sum" can arbitrary long numbers well.

regarding uniqueness, using standard crypt(3) function sha-512 , characters in set a-za-z./ have 54 different characters , 86 character long string 54^86 different values. that's lot :-)

(don't use 13 char long des crypt though, that's bruteforceable modern hardware , use "salt" values same input string gives different hash values , can't use "rainbow table" attack).


Comments

Post a Comment

Popular posts from this blog

blackberry 10 - how to add multiple markers on the google map just by url? -

i have android application, want convert blackberry 10 , google map needed in app,but blackberry 10 not support googlemap , blackberry developer web site supply way replace it.the sample below: @override public void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.main); webview webview = (webview) findviewbyid(r.id.mywebview); webview.getsettings().setjavascriptenabled(true); webview.loadurl("http://maps.google.com/?ll=36.97, -122&lci=bike&z=13&t=p"); } i cannot understand it,i not know how add multiple markers on googlemap via url? can me? this worked me map shown in webview.
Read more

php - guestbook returning database data to flash -

i've been struggling problem long , unable make work, hope can me it. first, know php files correct , mysql database works fine. in flash, able submit comment database comments not display. did many tests such making returned_database flash separately , worked fine - can see old comments. long combine submitting 1 , returning 1 together, flash doesn't show comments more. put lower version flash effects on frame thinking doesn't collaborate returning flash, submitting flash works fine. since pretty complex problem hard me copy actionscript code because on different frames in flash. if has ideas fixing maybe can send file you?
Read more

delphi - Dynamic file type icon -

i want register file type in windows , make program delphi draw icon of file according contents (something custom icon format). how can this? thanks nortd , user539484 comments, searched internet "shell icon handler delphi" , found sample here , , shell+ components has component this.
Read more