De or het cryptologie?

The correct Dutch article is:

de cryptologie

Rule Words ending in -logie: always de. See the rule
Meaning (Dutch) (informatica) leer van het geheimschrift

How to use cryptologie

the cryptologiede cryptologie
this cryptologiedeze cryptologie
that cryptologiedie cryptologie
our cryptologieonze cryptologie
your cryptologiejouw cryptologie
every cryptologieelke cryptologie
which cryptologie?welke cryptologie?
a big cryptologie / the big cryptologieeen grote cryptologie, de grote cryptologie

Meaning, plural, diminutive, pronunciation and translations: WikiWoordenboek (Dutch Wiktionary) (CC BY-SA 4.0). Example sentences: Tatoeba (CC BY 2.0 FR).