?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F322%2F&rft.title=Cryptographic+techniques+used+to+provide+integrity+of+digital+content+in+long-term+storage&rft.creator=Magorzata%2C+Bladoszewska&rft.creator=Tomasz%2C+Brozek&rft.creator=Michal%2C+Zajac&rft.creator=Lucyna%2C+Cieslik&rft.creator=Maria%2C+Donten-Bury&rft.creator=Kamil%2C+Kulesza&rft.creator=John%2C+Ockendon&rft.creator=Lukasz%2C+Stettner&rft.creator=Piotr%2C+Wojdyllo&rft.creator=Wladimir%2C+Zubkov&rft.subject=Information+and+communication+technology&rft.description=The+main+objective+of+the+project+was+to+obtain+advanced+mathematical+methods+to+guarantee+the+verification+that+a+required+level+of+data+integrity+is+maintained+in+long-term+storage.+The+secondary+objective+was+to+provide+methods+for+the+evaluation+of+data+loss+and+recovery.+Additionally%2C+we+have+provided+the+following+initial+constraints+for+the+problem%3A+a+limitation+of+additional+storage+space%2C+a+minimal+threshold+for+desired+level+of+data+integrity+and+a+defined+probability+of+a+single-bit+corruption.%0D%0A%0D%0AWith+regard+to+the+main+objective%2C+the+study+group+focused+on+the+exploration+methods+based+on+hash+values.+It+has+been+indicated+that+in+the+case+of+tight+constraints%2C+suggested+by+PWPW%2C+it+is+not+possible+to+provide+any+method+based+only+on+the+hash+values.+This+observation+stems+from+the+fact+that+the+high+probability+of+bit+corruption+leads+to+unacceptably+large+number+of+broken+hashes%2C+which+in+turn+stands+in+contradiction+with+the+limitation+for+additional+storage+space.%0D%0A%0D%0AHowever%2C+having+loosened+the+initial+constraints+to+some+extent%2C+the+study+group+has+proposed+two+methods+that+use+only+the+hash+values.+The+first+method%2C+based+on+a+simple+scheme+of+data+subdivision+in+disjoint+subsets%2C+has+been+provided+as+a+benchmark+for+other+methods+discussed+in+this+report.+The+second+method+(%22hypercube%22+method)%2C+introduced+as+a+type+of+the+wider+class+of+clever-subdivision+methods%2C+is+built+on+the+concept+of+rewriting+data-stream+into+a+n-dimensional+hypercube+and+calculating+hash+values+for+some+particular+(overlapping)+sections+of+the+cube.%0D%0A%0D%0AWe+have+obtained+interesting+results+by+combining+hash+value+methods+with+error-correction+techniques.+The+proposed+framework%2C+based+on+the+BCH+codes%2C+appears+to+have+promising+properties%2C+hence+further+research+in+this+field+is+strongly+recommended.%0D%0A%0D%0AAs+a+part+of+the+report+we+have+also+presented+features+of+secret+sharing+methods+for+the+benefit+of+novel+distributed+data-storage+scenarios.+We+have+provided+an+overview+of+some+interesting+aspects+of+secret+sharing+techniques+and+several+examples+of+possible+applications.&rft.date=2011&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F322%2F1%2FESGI77_STORAGE_report.pdf&rft.identifier=++Magorzata%2C+Bladoszewska+and+Tomasz%2C+Brozek+and+Michal%2C+Zajac+and+Lucyna%2C+Cieslik+and+Maria%2C+Donten-Bury+and+Kamil%2C+Kulesza+and+John%2C+Ockendon+and+Lukasz%2C+Stettner+and+Piotr%2C+Wojdyllo+and+Wladimir%2C+Zubkov++(2011)+Cryptographic+techniques+used+to+provide+integrity+of+digital+content+in+long-term+storage.++%5BStudy+Group+Report%5D+++++