Encryption/ciphers/codes in Chinese I am quite curious as to how you can perform simple encryption for the Chinese language.
Saw a similar question related to encryption/Chinese here: About cryptography in a character language, however the method of encryption appears to be quite complicated.
If I'm not mistaken, the method described in the answer above, requires something similar to a table which pre-maps certain characters to other characters; or the use of something like an One-time pad - both of which requires a fair amount of prior communication between both parties.
I was wondering if there is something simpler, what I have in mind is something like a Substitution cipher. That is, a way to encode the message easily, and also allowing the message to be decoded easily (if the secret key is known) or cracked given analysis or use of decoding techniques/knowledge.
For example, in English there are many ways to encrypt a message - some common/simple examples ROT13, Vigenere.
However, I can't seem to see how the concept of &quot;pulling apart&quot; a word can apply to Chinese characters.
For example, I can (fairly easily) encode the below using Vignere (key: chocolate), but how would I do so in Chinese?

I am learning Chinese --&gt; K ha nslrgmpn Qjwyeli
我在學中文 --&gt; ?
I take your question to mean, how both historically and in the modern age one could construct a pen-and-paper cipher using the Chinese language.

As pointed out in the question, Chinese is a logographic language and therefore has a far greater number of characters than Phonetic systems. Historically this has cause Chinese codes not to be based around the script.      

The following claims are taken from a forum discussion and translation of ancient Chinese codes for lack of a better source.


Nüshu script may not have been intended for secrecy but it functions as such since it was almost exclusively used and readable by educated Chinese women. It was phonetic and had a set of 700 characters. This suggests that one could use the phonetic attributes of the Chinese language as a basis for a reduced character set on top of which one could implement a code. 
In an earlier form of secret sharing, messages were cut into strips and delivered by different couriers.


  The so called “阴书” was to write the document vertically and cut it into 3 sections. Sent 3 persons, and each person would hold one of the sections. They would depart at different times and using different paths. When the receiver received all 3 parts, he could get the whole thing of this secret document. If one of the messengers was captured by the enemies, the enemy would have difficulties to understand the secret document. As translated by the Chinese History Forum

The technique of phrases is something I don't entirely understand I think the method is essentially to use the phonetic sound from ciphertext logographic characters to transmit a secret message. In English "eyesight hat very eight seashores create rat table" or "I ha-ve a se-cre-re-t" 


  “反切” (fan3 qie4) is a kind of phonetic system originated in ancient time to help document the pronunciation of Chinese language. The basic method for (fan3 qie4) is: Take the first word 上字 (shang4 zi4 - upper word) for its starting sound (or the consonant) and the second word (xia4 zi – lower word) for its ending sound (or the vowel). The tone would follow the ending sound. Therefore, a word is separated into two parts: 声母 (sheng mu3 – starting sound), 韵母 (yun4 mu3 – ending sound). Use the 声母 sheng mu adding a 韵母yun mu from another word to form the “反切” fan qie’s first word (or upper word). Use the 声母 sheng mu from another word adding a 韵母yun mu from this word to form the “反切” fan qie’s second word (or lower word). Use the lower word’s tone for the word’s tone. The first word’s starting sound and the second word’s ending sound is the pronunciation of the original word.  As translated by the Chinese History Forum

Code sticks were used in which each stick length represented a particular pre-agreed upon the message. These stick lengths could be transmitted using signal fires without actually having to physically send the stick. More generally this technique is equivalent to code books which were also used by the ancient Chinese. 


  For example, one-inch stick means victory. 9 inches stick means the army has broken the enemy army and captured the enemy generals. 8 inches stick means the enemy’s city (cities) has surrendered. 7 inches stick means successfully resisted the enemy’s army and the enemy’s army was gone. 6 inches stick means the army should be alert and defend the place diligently. As translated by the Chinese History Forum

Grille ciphers have often been remarked as excellent pen and paper ciphers for Chinese.      
While I can't find any historical reference to it, transposition ciphers seem completely compatible with the Chinese language. Although one would have to choose the words carefully because some meaning would leak out as whole words are transposed rather than letters.     
A method of enciphering Chinese characters similar to rot16 would be to write different characters on top of each other in different colors of ink. The key would state which color at each position was the correct character. For instance, the key could be 'blue-red-red-black-green-blue'. One of the interesting features of such a scheme is that one could design the cipher text such that all possible keys encode an apparently valid and readable message.  One advantage of this scheme would also be that it is secure against colorblind adversaries.