What you are describing is a known-plaintext attack. Modern ciphers can even be immune to chosen-plaintext attacks which is a much more potent attack than what you are describing.
I’m not qualified to judge the implementation of nostr DMs but if done correctly the could be secure
https://en.m.wikipedia.org/wiki/Known-plaintext_attack
https://en.m.wikipedia.org/wiki/Chosen-plaintext_attack
jonatan / Jonatan Werpers
npub1yd…57ez7
2023-01-20 22:15:22
in reply to nevent1q…5lqa
Author Public Key
npub1ydq5gpdz4n7kj2tsh7y377qfpkrydcnetmeg933lde95xzk5vtdqq57ez7Published at
2023-01-20 22:15:22Event JSON
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"pubkey": "23414405a2acfd692970bf891f78090d8646e2795ef282c63f6e4b430ad462da",
"created_at": 1674252922,
"kind": 1,
"tags": [
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"content": "What you are describing is a known-plaintext attack. Modern ciphers can even be immune to chosen-plaintext attacks which is a much more potent attack than what you are describing.\n\nI’m not qualified to judge the implementation of nostr DMs but if done correctly the could be secure\n\nhttps://en.m.wikipedia.org/wiki/Known-plaintext_attack\n\nhttps://en.m.wikipedia.org/wiki/Chosen-plaintext_attack",
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}