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Re: [rare-dev] ecdh vs dh


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  • From: Tim Chown <>
  • To: mc36 <>
  • Cc: Frédéric LOUI <>, "" <>
  • Subject: Re: [rare-dev] ecdh vs dh
  • Date: Fri, 16 Sep 2022 11:44:34 +0000
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You mean ones sent to multicast-discuss, or…? If you can give an example I
can check again.

Tim

> On 16 Sep 2022, at 12:29, mc36 <> wrote:
>
> ok then... just the juniper mails ares nor arriving to the lists according
> to frederic findings...
>
> On 9/15/22 10:28, Tim Chown wrote:
>> I meant in my own (Jisc) email, but I already get all yours Csaba.
>>> On 15 Sep 2022, at 06:25, mc36 <> wrote:
>>>
>>> good to know, thans... could you please whitelist the mx of
>>> nop.hu, mpls and juniper domains too?
>>> thanks,
>>> cs
>>>
>>>
>>> On 8/30/22 16:08, Tim Chown wrote:
>>>> Hi Christina,
>>>> I see all your emails marked as spam by my NREN s mail system. There
>>>> may be some problem with your IP reputation or something similar? Might
>>>> be related to the list and archiving issues.
>>>> I ve added a filter to prevent that happening in the future.
>>>> Tim
>>>>> On 29 Aug 2022, at 16:14, Cristina Klippel Dominicini
>>>>> <> wrote:
>>>>>
>>>>> Hi Csaba!
>>>>>
>>>>> I am happy to hear this :-)
>>>>>
>>>>> I sent the e-mail to my friends, but in the meanwhile I am
>>>>> investigating and found this track:
>>>>>
>>>>> Section 15.5, page 419
>>>>> https://shoup.net/ntb/ntb-v2.pdf
>>>>>
>>>>> "There are two other factoring algorithms not discussed here, but that
>>>>> should anyway at least be mentioned. The first is the elliptic curve
>>>>> method, introduced by Lenstra [60]. Unlike all of the other known
>>>>> subexponential-time algorithms, the running time of this algorithm is
>>>>> sensitive to the sizes of the factors of n; in particular, if p is the
>>>>> smallest prime dividing n, the algorithm will find p (heuristically) in
>>>>> expected time
>>>>> exp[( 2 + o(1))(log p log log p)1/2] len(n)O(1).
>>>>> This algorithm is quite practical, and is the method of choice when it
>>>>> is known (or suspected) that n has some small factors. It also has the
>>>>> advantage that it uses only polynomial space (unlike all of the other
>>>>> known subexponential-time factoring algorithms)."
>>>>>
>>>>> Best regards,
>>>>> Cristina
>>>>>
>>>>> ________________________________________
>>>>> De: mc36 <>
>>>>> Enviado: segunda-feira, 29 de agosto de 2022 11:12
>>>>> Para: ; Cristina Klippel Dominicini
>>>>> Assunto: Re: [rare-dev] ecdh vs dh
>>>>>
>>>>> ps: thanks for the math pdf you sent me a year ago or so...
>>>>> we learnt math in hungarian so it really helped me a lot!
>>>>>
>>>>> On 8/29/22 16:06, mc36 wrote:
>>>>>> thanks for confirming the reception of the mail...
>>>>>> and thanks for taking care of the question...
>>>>>> please take your time, it have a good change that
>>>>>> i\m not right so dont put too much effort into it,
>>>>>> just if it really catches an interest somewhere....
>>>>>> thanks,
>>>>>> cs
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 8/29/22 16:01, Cristina Klippel Dominicini wrote:
>>>>>>> Hi Csaba!
>>>>>>>
>>>>>>> Sorry for the delay. For some reason, I am not receiving all the
>>>>>>> threads from the rare list, and my mail server also blocked some
>>>>>>> messages. I will check the archives.
>>>>>>>
>>>>>>> Interesting question! I am honored by your mention as a skilled
>>>>>>> mathematician, but I am more a computer engineering trying to
>>>>>>> understand and apply the math concepts to computing
>>>>>>> problems :-D But I have some very skilled mathematician friends that
>>>>>>> help me when I have some doubts. I will check with them if they have
>>>>>>> any insights about your question and get
>>>>>>> back to you soon :-)
>>>>>>>
>>>>>>> Best regards,
>>>>>>> Cristina
>>>>>>>
>>>>>>> ________________________________________
>>>>>>> De:
>>>>>>> <> em nome de mc36 <>
>>>>>>> Enviado: sexta-feira, 26 de agosto de 2022 06:45
>>>>>>> Para: Cristina Klippel Dominicini
>>>>>>> Cc:
>>>>>>> Assunto: [rare-dev] ecdh vs dh
>>>>>>>
>>>>>>> hi,
>>>>>>>
>>>>>>> can i ask you to help me solve a long lived question of me please:
>>>>>>> (i ask you because you're the only well skilled mathematician i know)
>>>>>>> (if it's outside of your interest, please forward it someone)
>>>>>>>
>>>>>>> which is harder to find out both a and b:
>>>>>>>
>>>>>>> ( (g^a)^b) % p == ( (g^b)^a) % p
>>>>>>> where g is 2 or 5, p is a 8192 bit prime, both well known, a and b
>>>>>>> are both secrets
>>>>>>> here we are talking about positive integers
>>>>>>>
>>>>>>> or
>>>>>>>
>>>>>>> a*b == b*a
>>>>>>> here the computation is performed over 448bit elliptic curves
>>>>>>>
>>>>>>>
>>>>>>> my reasoning is that reversing the multiplication should be easier
>>>>>>> than solving the discrete logarithm problem
>>>>>>>
>>>>>>> i see that it is an apples to oranges kind of question so a weak
>>>>>>> conjecture is much more than enough
>>>>>>>
>>>>>>> thanks,
>>>>>>> cs
>>>>>>>
>>>>>>>
>>>>>>> ________________________________
>>>>>>>
>>>>>>> Esta mensagem (incluindo anexos) cont m informa o
>>>>>>> confidencial destinada a um usu rio espec fico e seu conte do
>>>>>>> protegido por lei. Se voc n o o destinat rio
>>>>>>> correto deve apagar esta mensagem.
>>>>>>>
>>>>>>> O emitente desta mensagem respons vel por seu conte do e
>>>>>>> endere amento.
>>>>>>> Cabe ao destinat rio cuidar quanto ao tratamento adequado. A
>>>>>>> divulga o, reprodu o e/ou distribui o sem a devida
>>>>>>> autoriza o ou qualquer outra a o sem conformidade
>>>>>>> com as normas internas do Ifes s o proibidas e pass veis de san
>>>>>>> o disciplinar, c vel e criminal.
>>>>>>>
>>>>>
>>>>>
>>>>> ________________________________
>>>>>
>>>>> Esta mensagem (incluindo anexos) cont m informa o confidencial
>>>>> destinada a um usu rio espec fico e seu conte do protegido por
>>>>> lei. Se voc n o o destinat rio correto deve apagar esta mensagem.
>>>>>
>>>>> O emitente desta mensagem respons vel por seu conte do e endere
>>>>> amento.
>>>>> Cabe ao destinat rio cuidar quanto ao tratamento adequado. A divulga
>>>>> o, reprodu o e/ou distribui o sem a devida autoriza o ou
>>>>> qualquer outra a o sem conformidade com as normas internas do Ifes s
>>>>> o proibidas e pass veis de san o disciplinar, c vel e criminal.




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