For example, the public key operation of RSA, which is done at the client (encoding the session key in the server's public key) is very highly optimized by using 0x10001 (1000000000000001) as the public exponent; this requires only 16 multiplies and one add. But the server must decrypt the session key with the server's private key, and even with the precomputed information in the certificate and the Chinese Remainder Theorem speedup this is a more expensive operation. This is an example of an expensive constant-time operation that is only done once, at the server, and could explain your observations.
If you really wanted that data, you should try starting the timer after the connection is opened but before sending data. This might require modification to the source code of the server.
Tyler Durden wrote:
Hello, I am trying to get the transfering time between a client and a server
with different size of data because I want to know that ciphers are
more efficient and after I can choose the cipher more efficient and
secures, because I want build a library for to transfer data in mobile
devices (PDA, ...).
But I don't understand the results that I have got; the time of the
transfering of the client more or less is proporcional to the size of
the data but in the server, this only it happens in two of the
differents size of data that I try, exactly with the two heavy sizes.
The different size that I try are 1 kb, 10kb, 100 kb, 1 Mb, 10 Mb.
My, answer is: The time of the transfer of data would have to be proporcional to the size of the data?
Thank very much! ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager [EMAIL PROTECTED]
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