Abstract In the French Army archives three cryptograms encrypted by the M-209 were found. They date from 1944 and come from the 1st French Army. Since the security rules in the military require them to be destroyed, it is extremely rare to have access to this type of document. This article aims to show the use of the M-209 in the French Army. It will first briefly describe the operation of the M-209 encryption machine and describe the cryptographic means used by the French Army during the Second World War, including the M-209 provided by the Americans. The three cryptograms found in the archives will then be studied. The various components of these messages are described, starting with the key groups (which provide the message key) and continuing to the main abbreviations as well as some codenames. The plaintexts will then become understandable. This article ends with the reconstruction of the keys (internal and external) of the first two messages. This reconstruction could not be completed for the third message: it is given as a challenge to the readers of Cryptologia. This is also the opportunity to balance the security of the M-209 with that of the Enigma.

中文翻译：

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正版法国二战 M-209 密码

摘要 在法国陆军档案中发现了三个由 M-209 加密的密码。它们的历史可以追溯到 1944 年，来自法国第一集团军。由于军队中的安全规则要求销毁它们，因此获得此类文件的机会极为罕见。本文旨在展示 M-209 在法国军队中的使用。它将首先简要介绍M-209加密机的操作，并介绍二战期间法国军队使用的加密手段，包括美国人提供的M-209。然后将研究档案中发现的三个密码。描述了这些消息的各个组成部分，从密钥组（提供消息密钥）开始，继续到主要缩写以及一些代号。然后明文将变得可以理解。本文以重构前两条消息的密钥（内部和外部）结束。对于第三条消息，此重构无法完成：它是对 Cryptologia 读者的挑战。这也是平衡 M-209 与 Enigma 安全性的机会。