javascript - Is it possible to produce a final SHA-256 value from a series of intermediate values? -

-

is possible produce multiple intermediate sha-256 values somehow combined @ later time produce same sha-256 produced single hashing computation?

in other words, if hash 4gb .iso image file sha-256 value 1 day, produce same single sha-256 splitting file into, lets 10 sections, producing intermediate sha-256 each section, , @ later time, produce final sha-256 using "only" intermediate sha-256 values?

i realise there no way produce 10 intermediate sha-256 values 1 final sha-256 value thought might possible hash file in chunks , combine 10 intermediate sha-256 values @ later time without needing actual data @ same time.

if possible, how produce final sha-256 intermediate sha-256 values in c# and/or javascript?

edit: want take away requirement of intermediate values being sha-256 values.

i don't care long can produce final sha-256 @ later time using "only" multiple intermediate values , no data. , have exact same sha-256 have gotten doing @ once on 4gb(arbitrary size) file.

i'm thinking of voucher system conductor asks see train ticket , have person step in place , say, "i've checked guy out, don't need to, verify integrity".

a hashing algorithm produces unique hash every input data. combination of intermediate hashes still different iso file, producing different hash if hash file directly.

if drop requirement hash produced file must same final hash produced intermediates, can still use later approach in opinion since combination of 10 hashes should still unique in , of itself, giving unique final hash each input file.

the scheme that:

enter image description here


Comments

Post a Comment

Popular posts from this blog

qt - Using float or double for own QML classes -

-
i've created components , helper methods using c++ , qt used in qml gui. of methods calculate gui elements (size, transformations, scene graph items creation). target arm 32 bit using opengl / eglfs render output. opengl using float , qml using real (defined double ). what should use in c++ do not lose precision? if use qreal ( double ) shouldn't lose precision. if git grep float in qtbase.git , can find out bit more: dist/changes-5.2.0-**************************************************************************** dist/changes-5.2.0-* important behavior changes * dist/changes-5.2.0-**************************************************************************** dist/changes-5.2.0- dist/changes-5.2.0- - qt compiled qreal typedef'ed double on dist/changes-5.2.0: platforms. qreal float on arm chipsets before. guarantees more dist/changes-5.2.0- consistent behavior between platforms qt supports, binary dist/chan...
Read more

Create Outlook appointment via C# .Net -

-
i need create outlook appointment using microsoft.office.interop.outlook , while can work locally on own workstation , works if run web application via server's browser, not work when connect server externally. hence, think might permission issue. i changed application pool identity " localsystem " don't access denied error. unfortunately, doesn't work. the app behaves if appointment created, appointment doesn't appear in outlook. here include file on top of aspx.cs page using outlook = microsoft.office.interop.outlook; here code using pop appointment. outlook.application apptapp = new outlook.application(); outlook.appointmentitem appt = apptapp.createitem(outlook.olitemtype.olappointmentitem) outlook.appointmentitem; appt.subject = txtfirstname.text + " " + txtlastname.text; appt.body = txtcomment.text; appt.alldayevent = false; appt.start = datetime.parse(txtreminderdate.text + " 8:00 am"); appt.end = datetime.p...
Read more

ios - Swift Array Resetting Itself -

-
i have 2 arrays: pointhistory , datehistory . have nstimer , , when timer runs out, action called. in action appending int pointhistory , , current date string datehistory . here timer action: func timeraction() { let steppervalue = int(stepper.value) employee.numberofpoints = steppervalue networking.saveemployee(employee, completion: { (error) -> void in if error != nil { let alert = uialertcontroller(title: "error", message: "there error updating \(self.employee.name)'s points", preferredstyle: .alert) let alertaction = uialertaction(title: "ok", style: .cancel, handler: nil) alert.addaction(alertaction) self.presentviewcontroller(alert, animated: true, completion: nil) } }) var dateformatter = nsdateformatter() dateformatter.dateformat = "mm-dd-yyyy" dateformatter.timezone = nstimezone.localtimezone() var date = nsdate() var ...
Read more