As early as in ancient times, our ancestors were able to record and transmit information through specific sounds, actions and even knots, which is the early prototype of intelligence.
In the information production in ancient China, the use of confidentiality means can be traced back to the "argot" in the late Shang Dynasty and early Zhou Dynasty, that is, the information content transmitted by an agreed secret signal or other substitute language. The argot is in the form of material objects. The usage of "Yin Fu" and "Yin Shu" is recorded in the military script "Six Taos". In the later development, it evolved into written form and oral form.
The early Yinfu was made of bamboo, and later it was replaced by wood chips and copper chips. The monarch and the front general secretly agree on what kind of information the different length of runes represent, and appoint a special person to deliver it. Since the Yinfu itself has no words or symbols, even if the sender is captured, the information itself is still safe. Although it is simple to operate and has high confidentiality, it has limited transmission content, and is only suitable for the transmission of small important information, which is not suitable for secret communication in complex military situations. Yin script can transmit more information than Yin script. According to the Six Taos, "All those who have serious concerns about evil things should use a book instead of a symbol." It means that all plots should use a yin script instead of a yin symbol. Yin script is actually a kind of military document. The production method is to first write the confidential content completely on the wooden slips or bamboo slips, then divide it into three copies and send it to three envoys. Only when the receiver has received all three parts can he know the whole content. This production method can avoid the information leakage caused by the capture of a messenger, but the capture of the messenger will also lead to the receiver being unable to obtain complete and effective information.
During the Spring and Autumn Period and the Warring States Period, a more effective means of information security emerged, namely, the mud sealing technology: after the bamboo slips or wooden slips with written characters are bound, special cement is applied to the knots, and then the seal of the submitter or department is stamped on the cement. The recipient mainly judges whether to leak the secret through the identification of the authenticity of the seal and the integrity of the seal. This method was simple, practical and inexpensive, and was widely used at that time. In the project list of "2020 National Top Ten Archaeological New Discoveries", Tomb 2 of Tushan, Xuzhou, Jiangsu, has attracted much attention. More than 4800 relics of various kinds have been unearthed from Tomb 2, including more than 4500 pieces of sealing mud found in the sealing soil.
After the Qin and Han Dynasties, information production usually used secret signs, ciphers, symbols and even small languages to encrypt, that is, the written form of "argot" mentioned above. According to the Wu Jing Zongyao written by the Song people, military intelligence in that period was equipped with passwords, that is, the number code "password book" of 1-40 was used to replace intelligence information. For example, ask for more troops, be surrounded, rebel, etc. This alternative operation is similar to Morse password. In the Yuan Dynasty, intelligence production began to use "Yisi for non characters", that is, Arabic instead of Chinese. Arabic, as a small foreign language, had specific rules and writing methods. Under the background of the times at that time, it was difficult to master without instruction and was convenient for confidentiality. Using a foreign language instead of the Ming language increases the cost of information production and also increases the difficulty of information interpretation.
In the Ming Dynasty, as a kind of official documents with high confidentiality, Mi Shu was widely used in political occasions. Compared with the normal titles and memorials, the contents of the secret book are only known by the superior and the emperor, the so-called "heaven knows and earth knows, you know and I know". Its handling method is also different from that of the general Zhang Zuo, which is usually sent from the hands of the upper Shu people to the front of the imperial court, and people in the middle are strictly prevented from "intercepting Hu". The Ming Dynasty attached great importance to the secret and sparse production and took various measures. In general, courtiers cannot write and transcribe secret texts on behalf of others, which is conducive to controlling the scope of knowledge of secret texts. In the late Ming Dynasty, there was a new way to keep secret, that is, to lock the outer seal of the secret seal or use a special box. However, the use of special boxes to convey secrets and secrets is only applicable between cabinet ministers and the emperor, which is not universal, but it also provides ideas and inspiration for adding folding boxes and padlocks in the process of presenting secret folding in the Qing Dynasty.
In the Qing Dynasty, in order to meet the needs of centralized monarchy, the memorial system was gradually established. Because there were often words such as "secret" on the surface and inside of the memorial, it was called "secret folding". The courtier must put the memorial in the envelope, then put it in the folding box and lock it well before giving it to others. Rao Songsheng's Folding Manual, written by Rao Xunxuan in the Qing Dynasty, describes the envelope as follows: "Please fold the envelope, use Yunlong yellow silk on the outside, and use yellow powder paper on the inside. It is six inches long and four cents wide, and the top and bottom heads are five cents wide." "The folding box is eight inches long and four inches wide, and one inch and five cents high. It is framed with yellow silk on the inside and painted with yellow paint on the outside." The second year of Yongzheng's reign (1724) In the November imperial edict, there was the words "I will make a leather case inside, send it to all officials, and order them to seal and play". Therefore, it can be seen that the secret book should have two layers inside and outside. The outside is a wooden box, and inside is a movable leather case that can be taken out. In the fifth year of Yongzheng's reign (1727), Changlai, the governor of Fujian, lost the key and had to borrow the lock from General Shi Liha. It can be seen that there is a lock outside the wooden box. In addition, when delivering important documents such as memorials, the Qing Dynasty also used envelopes such as "sealed barrels" and "plywood", which can play a very good role in confidentiality.
In ancient times, the confidentiality of military and political information was closely related to the consolidation of the feudal monarchy and the interests of the feudal dynasties. In the long years, a series of confidentiality systems and means for information production have been developing, and the feudal rulers' attention to confidentiality can be seen.
(Reprinted from the 9th issue of Confidentiality in 2021)
