algorithm - Ideal hashing method for wide distribution of values? -

-

as part of rhythm game i'm working, i'm allowing users create , upload custom songs , notecharts. i'm thinking of hashing song , notecharts uniquely identify them. of course, i'd few collisions possible, however, cryptographic strength isn't of importance here wide uniform range. in addition, since i'd performing hashes rarely, computational efficiency isn't big of issue.

is easy selecting tried-and-true hashing algorithm largest digest size? or there intricacies should aware of? i'm looking @ either sha-256 or 512, currently.

all cryptographic-strength algorithm should exhibit no collision @ all. of course, collisions exist (there more possible inputs possible outputs) should impossible, using existing computing technology, find one.

when hash function has output of n bits, possible find collision work 2n/2, in practice hash function less 140 bits of output cannot cryptographically strong. moreover, hash functions have weaknesses allow attackers find collisions faster that; such functions said "broken". prime example md5.

if not in security setting, , fear random collisions (i.e. nobody actively try provoke collision, may happen out of pure bad luck), broken cryptographic hash function fine. usual recommendation md4. cryptographically speaking, broken can be, non-cryptographic purposes devilishly fast, , provides 128 bits of output, avoid random collisions.

however, chances not have performance issue sha-256 or sha-512. on basic pc, process data faster hard disk can provide: if hash file, file reading bottleneck, not hashing. advice use sha-256, possibly truncating output 128 bits (if used in non-security situation), , consider switching function if performance-related trouble duly noticed , measured.


Comments

Post a Comment

Popular posts from this blog

ASP.NET/SQL find the element ID and update database -

-
basically i've got update query runs when click submit button. i have asp:repeater in page layer inside this <asp:repeater id="dgbookings" runat="server" onitemdatabound="itemdb"> <itemtemplate> <div class="bookingscontent"> <div class="bookingdetails" id="<%# databinder.eval(container.dataitem, "booking_ref") %>"> <p class="infotext"><%# databinder.eval(container.dataitem, "adults") %> <asp:linkbutton onclick="editdetails" text="edit..." runat="server"></asp:linkbutton></p> <p class="infotext"><asp:linkbutton onclick="submitdetails" text="submit..." runat="server"></asp:linkbutton></p> </div> </div> </itemtemplate> <asp:repeater> and outputs ...
Read more

jquery - appear modal windows bottom -

-
i have modal windows in application, work fine <div id="modal" class="modal hide fade" tabindex="-1" role="dialog" aria-labelledby="mymodallabel" aria-hidden="true"> but when modal appears, appear top of windows, , want appear bottom the application joomla 3.0! , using template of meet gavern any idea? i found solution i modified de css in bootstrap .modal.fade { top:-25%; -webkit-transition:opacity .3s linear, bottom .3s ease-out; -moz-transition:opacity .3s linear, bottom .3s ease-out; -ms-transition:opacity .3s linear, bottom .3s ease-out; -o-transition:opacity .3s linear, bottom .3s ease-out; transition:opacity .3s linear, bottom .3s ease-out; }
Read more

c++ - Compiling static TagLib 1.6.3 libraries for Windows -

-
i having super hard time compiling , using taglib 1.6.3 in qt project. i've tried can think of. taglib claims supported through cmake i'm not having luck. furthermore, i'm confused kinds of files need qt libs! i've built *.a files, *.lib, , *.dll. understand far... believe since i'm working in windows *.lib want. no matter do, end "undefined references" taglib functions try use when try compile qt project. have tried mingw32, msys, visual studio 2008, , cross-compiling windows on linux. turning nothing. what makes less sense me if compile same taglib source qt on mac (g++ think?) works fine! somewhere in windows compilation procedures have going wrong. have been smacking face on desk 30 (on , off) hours trying figure out. since qt uses mingw must compile taglib same compiler? if compile *.lib's visual studio not compatible? are *.a libraries usable in windows? (assuming mingw) i'm still trying handle on c++ stuff, after reading coun...
Read more