In the field of cryptanalysis, what is meant by a "rubber-hose" attack?

Forcing a keystream through an ASIC describes hardware-accelerated brute-force or stream cipher processing, which is a computational attack method unrelated to coercion.

A backdoor inserted by an algorithm's creator is called a trapdoor or kleptographic backdoor, which is a distinct design-level vulnerability unrelated to rubber-hose attacks.

Rubber-hose cryptanalysis refers to threatening or physically coercing a person - such as beating them with a rubber hose - to force disclosure of cryptographic keys or passphrases. It bypasses the mathematical strength of any encryption algorithm entirely by targeting the human who holds the secret rather than the ciphertext itself.

Making logical assumptions about plaintext content to break ciphertext describes a known-plaintext or crib-dragging attack, not a coercion-based technique.