During early World War I (1914–1916), Germany briefly experimented with ‘dotty’ and ‘dashy’ Morse, in essence adding a dot or a dash at the end of each Morse symbol. Each one was quickly broken by Allied SIGINT, and standard Morse was restored by Spring 1916.
That’s all it says on that Wikipedia article. It makes no sense to me. It’s implied that this was supposed to be some kind of encryption/cipher addition, but how is “adding a dot or a dash at the end of each Morse symbol” anything but “slightly incompatible” with the existing system? Something is not being told in that brief description.
Sure, it was ~1915, so they didn’t exactly have advanced computers yet, but what’s said above is at the level of what a child would come up with to “talk secretly” to their sibling without their parents understanding. Cryptography surely had existed as a concept (if only done with pen and paper, or with crude machines) for a long time by that time?