I roto i te 1972, i muri i te whakaoti i te rangahau i runga i te US kāwanatanga o te rorohiko haumaru hiahia, te US paerewa tinana NBS (National Bureau o Paerewa) -now huaina NIST (National Institute o Paerewa me te Hangarau) -identified te hiahia mo te paerewa kāwanatanga-whānui mō te whakamunatanga unclassified, mōhiohio tairongo. Na, i runga i te 15 o Mei 1973, i muri i te kōrero ki te NSA, tono NBS tono mō te whakamunatanga e e e tutuki paerewa hoahoa tino. kahore o nga tono, Heoi, puta ki te kia e tika ana. i tukuna he tono tuarua i runga i te 27 o Akuhata 1974. tenei wa, IBM tukua he kaitono i whakaaro whakaaetia -a whakamunatanga whakawhanakehia i roto i te wā 1973-1974 i runga i te hātepe o mua, i uru te Lucifer Feistel Horst DES.
tīmatanga o te tekau tau 1970