By design NOSTR private messaging does not hide non-content metadata. However a simple trick overcomes this limitation and allows one to emulate a flood protocol via NOSTR. This hack strongly anonymizes the participants so that an eavesdropper will have great difficulty trying to link senders and recipients of messages.

A group of participants must agree upon a public inbox represented by a single nostr npub identity (profile). The larger the group of participants is, the greater the anonymization strength grows.

All participants pre-encrypt their messages using the PGP public key of the recipient. The message must first be encrypted with PGP and one must of course not skip this step.

Then the pre-encrypted PGP messages are sent from a temporary NOSTR account to the public inbox account.

All users viewing the feed of the public inbox account will get all the encrypted messages, and will be able to decrypt the messages meant for themselves.

In this way it is not possible to link senders and receivers, providing strong privacy.

This is similar to the method of using the newsgroup alt.anonymous.messages. It has some advantages in that there are many nostr relays that allow anonymous access without paying or signing up, whereas there are only two free usenet servers that allow anonymous posting without an account. If desired all users can agree to use a single nostr relay for the inbox and the temporary sending profiles, which would add the the anonymity strength but would also present a single point of failure for denial of service attacks.

The public nostr inbox can be created by a single participant, or an anonymous participant can create the public inbox and publish the nostr private key for that inbox so that anyone can use it.

In order to circumvent ISP surveillance the users should employ a anonymizing network such as Tor, I2P, or Ygrdrassil to communicate with the nostr relays.

> Newsgroups: eternal-september.talk,rocksolid.shared.general
> Subject: Strong Anonymous Messaging Hack for NOSTR
> Date: Sat, 16 Mar 2024 04:05:36 -0500
> Organization: To protect and to server
> Message-ID: <ut3n5i$i91j$1@paganini.bofh.team>

eternal-september.talk ? :)

jn wrote:

>> Newsgroups: eternal-september.talk,rocksolid.shared.general
>> Subject: Strong Anonymous Messaging Hack for NOSTR
>> Date: Sat, 16 Mar 2024 04:05:36 -0500
>> Organization: To protect and to server
>> Message-ID: <ut3n5i$i91j$1@paganini.bofh.team>

> eternal-september.talk ? :)

I don't know why the op crossposted there :\

Because they can?

--
Retro Guy

On 3/23/2024 7:32 PM, Retro Guy wrote:
> jn wrote:
>
>>> Newsgroups: eternal-september.talk,rocksolid.shared.general
>>> Subject: Strong Anonymous Messaging Hack for NOSTR
>>> Date: Sat, 16 Mar 2024 04:05:36 -0500
>>> Organization: To protect and to server
>>> Message-ID: <ut3n5i$i91j$1@paganini.bofh.team>
>
>> eternal-september.talk ?  :)
>
> I don't know why the op crossposted there :\
>
> Because they can?
>

Doesn't Ray disallow crossposts outside of the eternal-september hierarchy?

Kyonshi wrote:

> On 3/23/2024 7:32 PM, Retro Guy wrote:
>> jn wrote:
>>
>>>> Newsgroups: eternal-september.talk,rocksolid.shared.general
>>>> Subject: Strong Anonymous Messaging Hack for NOSTR
>>>> Date: Sat, 16 Mar 2024 04:05:36 -0500
>>>> Organization: To protect and to server
>>>> Message-ID: <ut3n5i$i91j$1@paganini.bofh.team>
>>
>>> eternal-september.talk ?  :)
>>
>> I don't know why the op crossposted there :\
>>
>> Because they can?
>>

> Doesn't Ray disallow crossposts outside of the eternal-september hierarchy?

I'm not sure. The OP posted from Ivo's server:
Path: i2pn2.org!i2pn.org!paganini.bofh.team!tor-network!not-for-mai

That would allow them to crosspost between the groups. Whether e-s would then block the post when received from a peer, I don't know.

--
Retro Guy

On 4/17/2024 3:11 PM, Retro Guy wrote:
> Kyonshi wrote:
>
>> On 3/23/2024 7:32 PM, Retro Guy wrote:
>>> jn wrote:
>>>
>>>>> Newsgroups: eternal-september.talk,rocksolid.shared.general
>>>>> Subject: Strong Anonymous Messaging Hack for NOSTR
>>>>> Date: Sat, 16 Mar 2024 04:05:36 -0500
>>>>> Organization: To protect and to server
>>>>> Message-ID: <ut3n5i$i91j$1@paganini.bofh.team>
>>>
>>>> eternal-september.talk ?  :)
>>>
>>> I don't know why the op crossposted there :\
>>>
>>> Because they can?
>>>
>
>> Doesn't Ray disallow crossposts outside of the eternal-september
>> hierarchy?
>
> I'm not sure. The OP posted from Ivo's server:
> Path: i2pn2.org!i2pn.org!paganini.bofh.team!tor-network!not-for-mai
>
> That would allow them to crosspost between the groups. Whether e-s would
> then block the post when received from a peer, I don't know.
>

I checked and it showed up over there. Of course it might show up over
there because I use Hamster and have both E-S and i2pn2.org connected.