Ko te tohatoha kī matū (QKD) he tikanga whakawhitiwhiti kōrero haumaru e whakamahi ana i tētahi kawa whakamuna e whakauru ana i ngā wāhanga o te miihini matū. Mā tēnei ka taea e ngā rōpū e rua te whakaputa i tētahi kī ngaro matapōkere kua tohaina e mōhiotia ana e rāua anake, ka taea te whakamahi hei whakamuna me te wetewete i ngā karere. He maha ngā wā ka kiia he whakamuna matū, nā te mea koinei te tauira tino rongonui o tētahi mahi whakamuna matū.
Ahakoa e wātea ana mō ngā tau maha ki te hokohoko, kei te haere tonu te ahunga whakamua ki te hanga i ēnei pūnaha kia iti ake, kia iti ake te utu, kia kaha hoki ki te whakahaere i ngā tawhiti roa. He mea nui katoa ēnei mō te whakamahi a ngā kāwanatanga me ngā umanga i ēnei hangarau. Ko te whakaurunga o ēnei pūnaha QKD ki roto i te hanganga whatunga o nāianei te wero o nāianei, ā, kei te mahi ngā tīma maha-mātauranga o ngā kaihanga taputapu whakawhitiwhiti kōrero, ngā kaiwhakarato hanganga nui, ngā kaiwhakahaere whatunga, ngā kaiwhakarato taputapu QKD, ngā tohunga haumarutanga mamati me ngā kaipūtaiao ki tēnei.
Mā te QKD ka taea te tohatoha me te tiritiri i ngā kī ngaro e tika ana mō ngā kawa whakamuna. Ko te mea nui i konei ko te whakarite kia noho tūmataiti, arā, i waenga i ngā rōpū whakawhitiwhiti kōrero. Hei mahi i tēnei, ka whakawhirinaki mātou ki te mea i kitea i mua ko te raruraru o ngā pūnaha irahiko; ki te "titiro" koe ki a rātou, ki te whakararuraru rānei i a rātou i tētahi ara, ka "pakaru" koe i ngā āhuatanga irahiko.