Re: Converting ECC public key point-compressed and uncompressed

2011-07-18 Thread Erwin Himawan
I am able to convert the ECC key from compressed to uncompressed (and vice
versa) using the "EC_KEY_set_conv_form" call .


On Sun, Jul 17, 2011 at 10:30 AM, Erwin Himawan  wrote:

> Marti, thanks for your response.
>
> Erwin
>
> --**
> From: "Martin Boßlet" 
> Sent: Sunday, July 17, 2011 7:21 AM
> To: 
> Subject: Re: Converting ECC public key point-compressed and uncompressed
>
>
>  My understanding is that to convert the form of ecc key from compressed to
>>> uncompressed and from uncompressed to compressed require the knowledge of
>>> the ECC private key.
>>> Is my understanding correct?
>>>
>>
>> You might want to have a look at sections 2.3.3 and 2.3.4 in
>>
>> http://www.secg.org/download/**aid-780/sec1-v2.pdf<http://www.secg.org/download/aid-780/sec1-v2.pdf>
>>
>> No knowledge of the private key is needed.
>>
>> Regards,
>> Martin
>> __**__**
>> __
>> OpenSSL Project http://www.openssl.org
>> User Support Mailing Listopenssl-users@openssl.org
>> Automated List Manager   majord...@openssl.org
>>
>
>


Re: Converting ECC public key point-compressed and uncompressed

2011-07-17 Thread Erwin Himawan

Marti, thanks for your response.

Erwin

--
From: "Martin Boßlet" 
Sent: Sunday, July 17, 2011 7:21 AM
To: 
Subject: Re: Converting ECC public key point-compressed and uncompressed

My understanding is that to convert the form of ecc key from compressed 
to

uncompressed and from uncompressed to compressed require the knowledge of
the ECC private key.
Is my understanding correct?


You might want to have a look at sections 2.3.3 and 2.3.4 in

http://www.secg.org/download/aid-780/sec1-v2.pdf

No knowledge of the private key is needed.

Regards,
Martin
__
OpenSSL Project http://www.openssl.org
User Support Mailing Listopenssl-users@openssl.org
Automated List Manager   majord...@openssl.org 


__
OpenSSL Project http://www.openssl.org
User Support Mailing Listopenssl-users@openssl.org
Automated List Manager   majord...@openssl.org


Re: Converting ECC public key point-compressed and uncompressed

2011-07-17 Thread Martin Boßlet
> My understanding is that to convert the form of ecc key from compressed to
> uncompressed and from uncompressed to compressed require the knowledge of
> the ECC private key.
> Is my understanding correct?

You might want to have a look at sections 2.3.3 and 2.3.4 in

http://www.secg.org/download/aid-780/sec1-v2.pdf

No knowledge of the private key is needed.

Regards,
Martin
__
OpenSSL Project http://www.openssl.org
User Support Mailing Listopenssl-users@openssl.org
Automated List Manager   majord...@openssl.org


Re: Converting ECC public key point-compressed and uncompressed

2011-07-17 Thread Erwin Himawan
I did dig arround more on the ecparam and ec options.  Having a limited
knowledge on cryptograpy and specifically ecc key algorithm, and
experimenting with the CLI, I would like to clarify my understanding on
coverting the form of ecc key from compressed to uncompressed and vice
versa.

My understanding is that to convert the form of ecc key from compressed to
uncompressed and from uncompressed to compressed require the knowledge of
the ECC private key.
Is my understanding correct?

Thanks in advance

Erwin

On Fri, Jul 15, 2011 at 9:06 PM, Erwin Himawan  wrote:

> Hi All,
>
> I would like to know whether openssl API has function call for generating
> ECC point-compression given that only the uncompressed ECC public key.
>  Likewise, given the point-compressed ECC Key, I would also like to recover
> the uncompressed ECC key.
>
> Thanks for the help
>
> Regards,
> Erwin
>


Converting ECC public key point-compressed and uncompressed

2011-07-15 Thread Erwin Himawan
Hi All,

I would like to know whether openssl API has function call for generating
ECC point-compression given that only the uncompressed ECC public key.
 Likewise, given the point-compressed ECC Key, I would also like to recover
the uncompressed ECC key.

Thanks for the help

Regards,
Erwin