Classical ciphers, such as the Vigenère cipher, are weak and no longer used. They can be broken by using frequency analysis, which is a well-known fact.
However, frequency analysis often depends on the number of captured ciphertexts and/or their duplication. What if the ciphertext was compressed by an algorithm such as Huffman encoding，
lzma before encrypting the plaintext? For better security, assume there is no constant header, magic number, or any identifier in the plaintext.
How much more difficult does compression make attack by frequency analysis?