Research Of Software Watermarking Technology Based On Dynamic Graph

With the rapid development of hi-tech,such as,communication technology,computerscience technology,many software products are having been developed to serve our daily life.Software product has many advantages to people,for example,non-wear,agingresistance,accuracy,repeatability,and so forth,thus people are becoming more and moredepending on these software products.But many people get the right to use these software bythe back-door way,such as illegally copying, hostile attacking,stealing,tamperingand so on.These illegal acts have brought a good deal of losses to the owner of softwareproducts,both the spirit and money.In such circumstances,software protection is becoming notime to delay.Traditional software protection technologies mainly have serial number protection,timeand function limitation,registration protection,compact disk software protection,networksoftware protection,software watermarking,and the like.Software watermarking technology isa kind of effective software protection technology,and has the superiority as to traditionaltechnologies.Dynamic graph software watermarking belonging to dynamic watermarking is aresearch hotspot in the field of software watermarking.Dynamic graph watermarking iscreated dynamically in the execution of program,and has the non-trapping property, whichleading to very difficult to locate,analysis for those malicious attacker,and further tostealing,tampering,using.This paper at first simply presented the fundamental and basal concepts about softwarewatermarking,including the specific definition,general model,different classification,attackingpatterns and protection technology,evaluation index of watermarking scheme.Then introducedthe research key point----dynamic graph watermarking,and stated detailedly the theoreticalbasis,experimental procedure,CT algorithm,several common coding structures.Based on the advantage and disadvantage of the several coding structures,the paper proposed a improvedKPPCT coding scheme,as short for IKPPCT.The IKPPCT coding scheme referenced theKPPCT coding scheme to some extent,and altered the data coding structure,expanded theattribute fields for participating coding,therefore improved the data coding rate greatly.Thepaper in chapter four stated clearly the characters of the IKPPCT coding structure,experimental procedure of new coding scheme,application of the tamper-proofing idea.In thiscoding scheme, experimental procedure included the following,selecting watermarking value,encrypting watermarking value by RSA encryption algorithm,segmenting watermarking valueinto several small parts,searching for proper marking points to embed,embedding thewatermarking codes,extracting the original watermarking value.At last executing theimportant verification part from six aspects:safety,invisible,data coding rate,the maximumwatermarking value,performance overload,robustness.Theoretical analysis and experimentalresults show this improved coding scheme is desirable and effective.Almost every coding scheme has the inevitable disadvantage,so we should select themost proper coding structure to embed the dynamic graph watermarking,and at the same caneffectively protect the embedded watermarking.One of the innovation points of the paper wasimproving the KPPCT coding scheme which promoted the data coding rate.The anotherinnovation point is adding opaque predicates and opaque functions which belongs to thetamper-proofing technology field to protect dynamic graph watermarking.