It's a well-established (understatement of the century) shorthand for the term "cryptography", that no honest cryptocurrency enthusiast can claim in good faith to be ignorant of, because cryptography provides the technological foundations on which all cryptocurrencies are built.
Conflating these terms can cause undue confusion that breeds disdain for the very technology you're trying to promote. I, for one, was expecting to read an article on the history of cryptography as it evolved over the years when I clicked the link.
Despite all this, I just wanted to say the article itself was an interesting read, but you're doing yourself and the cryptocurrency community a disservice by unwittingly pulling a bait and switch like this on so many potential readers.
At the very least, please avoid using it as a shorthand in contexts intended for communication to those outside your community.