Masu binciken Poland sun ba da shawarar sabuwar hanyar hanyar sadarwa ta steganography dangane da fasalulluka na ka'idar layin sufuri na TCP da aka yi amfani da ita. Marubutan aikin sun yi imanin cewa makircinsu, alal misali, za a iya amfani da su wajen aika da boyayyen sakonni a cikin kasashen da ke da cikakken iko da ke sanya takunkumin intanet mai tsauri. Bari mu yi ƙoƙari mu gano abin da, a gaskiya, ƙirƙira ta ƙunshi da kuma yadda amfani da gaske yake.
Da farko, kana buƙatar ƙayyade abin da steganography yake. Don haka, steganography shine kimiyyar saƙon ɓoye. Wato ta hanyar amfani da hanyoyinta, jam’iyyun suna kokarin boyewa gaskiyar canja wuri. Wannan shine bambanci tsakanin wannan kimiyya da cryptography, wanda yayi ƙoƙari ya sa abun cikin saƙo ba zai iya karantawa ba. Shi ne ya kamata a lura da cewa ƙwararrun al'umma na cryptographers ne quite raini da steganography saboda kusanci da akidar zuwa ga ka'idar "Tsaro ta hanyar m" (Ban san yadda yake sauti daidai a cikin Rashanci, wani abu kamar "Tsaro ta hanyar jahilci). ”). Wannan ƙa'ida, alal misali, Skype Inc. - An rufe lambar tushe na mashahurin dialer kuma babu wanda ya san ainihin yadda ake rufaffen bayanai. Kwanan nan, ta hanyar, NSA ya koka game da wannan, wanda sanannen masanin Bruce Schneier. a cikin blog dina.
Komawa zuwa steganography, bari mu amsa tambayar dalilin da yasa ake buƙatar shi kwata-kwata, idan akwai cryptography. Tabbas, yana yiwuwa a ɓoye saƙo ta amfani da wasu algorithm na zamani, kuma lokacin amfani da isasshen dogon maɓalli, babu wanda zai iya karanta wannan saƙon sai dai idan kuna so. Duk da haka, wani lokacin yana da amfani a ɓoye ainihin gaskiyar watsawa. Misali, idan hukumomin da abin ya shafa suka katse saƙon da aka ɓoye, ba za su iya ɓoye shi ba, amma da gaske suna so, to a ƙarshe akwai hanyoyin da ba na kwamfuta ba na tasiri da fitar da bayanai. Yana sauti anti-utopian, amma, kun ga, wannan yana yiwuwa a bisa manufa. Don haka, zai fi kyau a tabbatar da cewa wadanda bai kamata su sani ba kwata-kwata an yi canjin wurin. Masu bincike na Poland sun ba da shawarar irin wannan hanya. Haka kuma, suna bayar da yin hakan ta hanyar amfani da ka'idar da kowane mai amfani da Intanet ke amfani da shi sau dubu a rana.
Anan mun zo kusa da Ka'idar Kula da Watsawa (TCP). Bayyana duk cikakkun bayanai, ba shakka, ba shi da ma'ana - tsawo, m, waɗanda suke buƙatar shi sun riga sun sani. A takaice, zamu iya cewa TCP yarjejeniya ce ta sufuri (watau yana aiki "sama" IP da "karkashin" ka'idojin Layer Layer, irin su HTTP, FTP ko SMTP), wanda ke ba da ingantaccen isar da bayanai daga mai aikawa zuwa ga mai karɓa. Amintaccen bayarwa yana nufin cewa idan fakiti ya ɓace ko canza, to TCP yana kula da tura fakitin. Lura cewa canje-canje a cikin kunshin nan baya nufin murdiya bayanai da gangan, amma kurakuran watsawa waɗanda ke faruwa a matakin jiki. Misali, yayin da fakitin ke tafiya akan wayoyi na jan karfe, wasu ragi biyu sun canza darajar su zuwa akasin haka ko kuma sun ɓace gaba ɗaya a cikin hayaniyar (a hanya, don Ethernet, ƙimar Kuskuren Bit yawanci ana ɗaukar kusan 10-8). ). Asarar fakiti a cikin hanyar wucewa kuma abu ne da ya zama ruwan dare gama gari akan Intanet. Yana iya faruwa, alal misali, saboda yawan aiki na masu amfani da hanyoyin sadarwa, wanda ke haifar da cikar buffer kuma, a sakamakon haka, kin amincewa da duk sabbin fakiti masu zuwa. Yawanci, adadin fakitin da suka ɓace kusan 0.1% ne, kuma a ƙimar kashi biyu cikin ɗari, TCP ya daina aiki kullum kwata-kwata - komai zai yi matukar jinkiri ga mai amfani.
Don haka, mun ga cewa turawa (sake aikawa) na fakiti abu ne mai yawa kuma gabaɗaya dole ga TCP. Don haka me yasa ba za a yi amfani da shi ba don bukatun steganography, duk da cewa TCP, kamar yadda aka ambata a sama, ana amfani dashi a ko'ina (bisa ga ƙididdiga daban-daban, a yau rabon TCP akan Intanet ya kai 80-95%). Ma'anar hanyar da aka tsara shine aika saƙon da aka tura ba abin da ke cikin fakiti na farko ba, amma bayanan da muke ƙoƙarin ɓoyewa. A lokaci guda, ba shi da sauƙi don gano irin wannan canji. Bayan haka, kuna buƙatar sanin inda za ku duba - adadin haɗin TCP na lokaci ɗaya da ke wucewa ta hanyar mai ba da sabis yana da girma. Idan kun san kusan matakin sake watsawa a cikin hanyar sadarwar, to zaku iya daidaita tsarin isar da saƙon steganographic ta yadda haɗin ku ba zai bambanta da sauran ba.
Tabbas, wannan hanya ba ta da lahani. Alal misali, daga ra'ayi mai amfani, ba zai zama mai sauƙi don aiwatar da shi ba - zai buƙaci canji a cikin tsarin cibiyar sadarwa a cikin tsarin aiki, ko da yake babu wani abu mai rikitarwa a cikin wannan. Bugu da ƙari, idan kuna da isassun albarkatun, har yanzu kuna iya gano fakitin "asiri", don haka kuna buƙatar dubawa da bincika kowane fakiti akan hanyar sadarwa. Amma a matsayinka na mai mulki, wannan kusan ba zai yiwu ba, don haka yawanci suna neman wani abu wanda ya fito don fakiti da haɗin kai, kuma hanyar da aka tsara kawai ta sa haɗin ku ya zama abin ban mamaki. Kuma babu wanda ya dame ku don ɓoye bayanan sirri kawai idan akwai. A wannan yanayin, haɗin kanta na iya kasancewa ba a ɓoye don tada ƙaramin zato.
Mawallafa na aikin (ta hanyar, ga masu sha'awar, Ta) ta nuna a matakin kwaikwayo cewa hanyar da aka tsara tana aiki kamar yadda aka yi niyya. Wataƙila a nan gaba wani zai shiga cikin aiwatar da ra'ayoyinsu a aikace. Sannan kuma, da fatan, za a sami raguwar tantancewa a Intanet.
source: www.habr.com