A message is plaintext (sometimes called cleartext). The process of disguising a message in such a way as to hide its substance is encryption. An encrypted message is ciphertext. The process of turning ciphertext back into plaintext is decryption. This is all shown in Figure 1.1.
You explain why it's called crypto... When you see the transaction ID, you can't know the private keys of the address that sends that coin, since the information on the transactions is encrypted i think crypto is the right way to call it. And it doesn't only use cryptography for the transactions, we see cryptography in the address generation and in some other process in the blockchain. So, for me, crypto is the right therm for this technology.