At the end of 1974, the Politburo decided to launch the Central Highlands Campaign in the spring of 1975. In compliance with the directive of the General Staff of the Vietnam People's Army, on January 10, 1975, the Cipher Department (General Staff) directed the Code Department to send a working group of 7 comrades to serve the A75 Group (commanded by General Van Tien Dung, Chief of the General Staff) to secretly enter the Central Highlands to study and organize the implementation of the Politburo's strategic determination. Thousands of directive telegrams from the Central Military Commission, the General Command and telegrams reporting the battlefield situation of A75 were encrypted, decoded, and secretly, accurately and promptly transmitted by the Code Department. On March 10, 1975, the Spring 1975 General Offensive and Uprising opened with the Central Highlands Campaign with a daring and unexpected battle in Buon Ma Thuot town. In this campaign, the officers and staff of the Code Translation Department made an important contribution to ensuring complete secrecy of intentions and combat plans, promptly translating incoming and outgoing messages, serving the leadership, direction, and command, creating a state of surprise for the campaign to achieve a resounding victory.

Telegram of General Vo Nguyen Giap on April 7, 1975. Photo: Archive

At the General Headquarters, at the end of March 1975, at the request of the General Command, in order to promptly encode and transmit important messages from the Politburo, the Central Military Commission, and the General Command to the battlefields, the Code Department sent a cryptographic team to the Central Military Commission to work. Here, the most urgent and top secret messages were all encoded, decoded, and transmitted accurately, promptly, and safely by the cryptographic team with the following signatures: Ba (Le Duan); Truong Chinh; To (Pham Van Dong); Van (Vo Nguyen Giap); Thanh (Hoang Van Thai); sent to comrades: Sau (Le Duc Tho); Bay Cuong (Pham Hung); Tuan (Van Tien Dung)...

The cryptographic team coded and transmitted top secret, extremely important, urgent telegrams from the Party, the Central Military Commission, and the General Command. There were telegrams written by Comrade Le Duan himself; General Vo Nguyen Giap personally delivered the telegram to the cryptographic team, and sometimes Comrade Cao Van Khanh, Deputy Chief of the General Staff, or combat officers delivered them. There were telegrams that General Vo Nguyen Giap wrote a paragraph and gave them to the cryptographic team to encode so that the information department could transmit that paragraph. The telegrams arrived and were translated by the cryptographic team and immediately transmitted them to the leaders. Many telegrams were very long but the requirement for transmission was very urgent, every minute had to be taken advantage of, such as the telegram sent by Comrade Le Duc Tho on April 25, 1975, 10 typewritten pages long, reporting on the situation on the B2 battlefield. There were telegrams 15-20 pages long, handwritten under very urgent conditions, requiring meticulousness and carefulness from cryptographic officers and staff. Although the work is very hard and the work is extremely urgent, being able to directly serve the leaders of the Party, State and Army at the General Headquarters is a great honor and pride for the officers and employees of the Cipher Department in general and the Code Translation Department at the General Headquarters in particular.

Following the rapid footsteps of each army, news of victory from the battlefields was continuously reported. The working atmosphere of the secret service at the General Headquarters was extremely urgent. The workload increased rapidly, and officers and employees deployed documents immediately. The speed of code translation was constantly increased: Seven minutes, six minutes, five minutes... Even more than four and a half minutes for a telegram. Shortening one minute at this time was extremely valuable. There were many highly urgent telegrams sent to the army wings, urging all directions to increase the speed of attack. At the Eastern Wing Command, upon receiving the secret telegram, comrade Le Trong Tan happily hugged the secret service officer Vu Van Canh and wrote on the telegram: "Cheers to the secret service, the information is very timely". In particular, at 9:30 a.m. on April 7, 1975, the General Headquarters' secret code of the urgent telegram No. 157/TK of General Commander-in-Chief Vo Nguyen Giap conveyed the order to the units on the battlefield: "Fast, faster, bolder, bolder, seize every hour and minute, rush to the front, liberate the South. Determined battle and total victory. Immediately convey to party members and soldiers".

Researchers of the Cipher Department discuss the technical and tactical features of the newly completed cryptographic product. Illustration photo: qdnd.vn

On April 14, 1975, the Politburo and the Central Military Commission approved the plan to liberate Saigon-Gia Dinh. The Code Department coded the Politburo's telegram No. 37/TK and sent it to the Campaign Command. At 7:00 p.m. the same day, the Campaign Command received a telegram with the following content: "Agree to name the Saigon Campaign the Ho Chi Minh Campaign." On the afternoon of April 15, at the Supreme Command Headquarters, General Vo Nguyen Giap gave instructions and assigned tasks to comrade Nguyen Duy Phe, Director of the Cipher Department: “In the recent days of particularly urgent fighting of our army and people on the Southern front, the officers, soldiers, and cipher staff have excellently completed their tasks. The Central Military Commission commends you comrades. The fight is currently continuing and the closer it gets to the day of total victory, the more urgent and fierce it becomes. The task of ensuring the secrecy, accuracy, and timeliness of the content of orders, the leadership and command of the Politburo, the Central Military Commission, and the General Command is of decisive significance to the implementation of the determination to liberate the South. All comrades, officers, soldiers, party members, union members, and staff of the Cipher Department must have great determination and find every way to ensure that requirement is met.”

In compliance with the Commander-in-Chief's directives, the General Headquarters' cryptographic staff determined their responsibilities, trained their will, improved their professional capacity, strived, each person worked as two, determined to complete the assigned tasks well and excellently. The cryptographic team was constantly on duty to translate codes from the General Headquarters to the battlefields and vice versa. Despite the stress and continuous work, the cryptographic staff were still careful to ensure the accuracy of every word, every idea, every punctuation mark, reminding each other to be extremely careful, because if just one word or one idea was wrong, the consequences would be unpredictable. The telegrams were promptly sent to the battlefields throughout the South as both orders and as an urging to the officers and soldiers on the front lines.

On April 22, 1975, the Code Translation Department of the Cipher Bureau coded a telegram from the Politburo signed by First Secretary Le Duan and sent to the Campaign Command: "The military and political opportunity to launch an attack on Saigon is ripe, we need to seize every day, promptly launch attacks on the enemy in all directions, do not delay, you guys immediately issue instructions for timely action directions".

At 11:00 a.m. on April 24, the General Headquarters' cipher team translated the telegram of Commander-in-Chief Vo Nguyen Giap with the content: General offensive on Saigon. At 5:00 a.m. on April 29, our troops simultaneously opened fire and attacked Saigon. The cipher team coded and transmitted the telegram of the Politburo and the Central Military Commission to the Ho Chi Minh Campaign Command: "The Politburo and the Central Military Commission send their greetings of victory to all cadres, soldiers, party members, and union members. Comrades, please bravely advance to win victory for the historic campaign named after the great Uncle Ho."

At 10 o'clock the same day, the Cipher Team coded and sent Telegram No. 149/TK of the Politburo and the Central Military Commission to the Ho Chi Minh Campaign Command with the following content: "Comrades, order our troops to continue attacking Saigon as planned. Advance with the most powerful spirit! Liberate and occupy the entire city. Disarm the enemy army, dissolve the enemy's government at all levels, completely crush all their resistance. Announce the placement of Saigon-Gia Dinh city under the authority of the Military Management Committee chaired by General Tran Van Tra".

At 10:30 a.m. on April 30, the General Headquarters' Cipher Team translated and forwarded the telegram from the Politburo and the Central Military Commission to the Ho Chi Minh Campaign Command with the content: "Force puppet President Duong Van Minh to surrender unconditionally". An hour later, comrade Nguyen Duy Phe, Director of the Cipher Department, read the telegram from comrade Le Trong Tan, Deputy Chief of the General Staff, Deputy Commander of the Ho Chi Minh Campaign, reporting: A unit of the Eastern Wing Command had planted the Liberation Army flag on the roof of the Independence Palace...

The 55 days and nights of the 1975 Spring General Offensive and Uprising used a large force and a very wide battlefield, marching and fighting at an unprecedented speed in the history of the nation; requiring urgent and continuous direction and command. Every officer and staff of the General Command's headquarters, forward command posts or units sent to serve the directions and spearheads following the rapid-fire troops on the battlefield, all promoted a sense of responsibility, did not fear hardships and sacrifices, and excellently completed their tasks, organizing the translation of nearly 160,000 telegrams, of which over 70% were urgent. The General Headquarters' cipher department alone translated, transmitted, received and delivered nearly 41,000 telegrams promptly, accurately, secretly and safely, of which over 600 were urgent telegrams, 139 were special telegrams and over 2,000 were urgent telegrams immediately translated. In April 1975, every 80 seconds, a telegram was translated by a cipher, meeting all the leadership, direction and command requirements of the Politburo, the Central Military Commission, and the General Command for the battlefields, contributing worthily to the common victory of the nation, fulfilling President Ho Chi Minh's wish to "fight to drive out the Americans, fight to overthrow the puppets".

HOANG VAN QUAN

    Source: https://www.qdnd.vn/quoc-phong-an-ninh/xay-dung-quan-doi/co-yeu-quan-doi-phuc-vu-tong-hanh-dinh-gop-phan-lam-nen-dai-thang-826057