What part of speech is cryptanalysts?
what signals the part of speech for cryptanalysts?
what does cryptanalysts mean?

A Cryptanalyst is a Noun.

Verb signals the part of speech for cryptanalysts

A Specialist in decoding secret messages, without prior knowledge of the key.

Explanation:

Generally, the noun is a part of speech that identifies a person, place or thing, or names.  Without nouns, you will be left with verbs, adjectives, and adverbs. Without things, you will be left with action words, descriptors, and modifiers.

The absence of things will annihilate any subject or article from your sentence which is in the same class as correspondence basically nothing. Cryptanalyst can be utilized as a thing since it signifies an individual.

In addition, you will realize that the cryptanalyst is a thing in the sentence since it decides an individual who is an expert in interpreting mystery messages. Especially those using figures and codes.

- "he is a very real person and his intent isn't to influence us vonnegut addresses this towards the end of the letter when he says, if we choose to curse, that is by our own individual means."