[VOIPSEC] What % of voip apps or devices actually use SRTP or ZRTP to encrypt audio calls

[Vijay K. Gurbani]

On 12/02/2010 07:59 AM, SM wrote:
> Hi,
>
>    I was wondering about what percentage of voip apps or devices actually use
> SRTP or ZRTP to encrypt audio calls in 2010. Are there any confirmed
> statistics for this? Has any study been done on this? Can I and where can I
> get such data?

Hi: I have gathered statistics from previous SIP interoperability events
on the support for SRTP, including specific keying mechanisms (SDES,
DTLS-SRTP).  Table I, reproduced below is from [1] and has been
augmented with the latest SIP interoperability event held last month.

I suspect that this is the closest you will get to public data on
support for SRTP.

+----------------+-----------------+-----------+------+-----------+
| SIPit number   | Total unique    | SRTP      | SDES | DTLS-SRTP |
| (date)         | implementations | Supported |      |           |
+----------------+-----------------+-----------+------+-----------+
   18 (Apr. 2006)         73           10          7        0
   19 (Oct. 2006)         90           12          P1       0
   20 (Apr. 2007)         90            9          4        1
   21 (Nov. 2007)         70           17          0        0
   22 (Apr. 2008)         80           32          P2       0
   23 (Oct. 2008)         50            8          0        1
   24 (May  2009)         43           16          0        1
   25 (Sep. 2009)         42           14          4        0
   26 (May  2010)         42           23          23       0
   27 (Nov. 2010)*        34           23          20       0

P1 Exact number unknown, SIPit 19 archives state "Keying was predominantly
    SDES."
P2 Exact number unknown, SIPit 22 archive states "Most of the tests
    established the session using SDES."
*  1 implementation supported keying using MIKEY.  2 ZRTP
    implementations observed.

   NB: Data for this table gathered from SIPit official website at
   https://www.sipit.net/SIPitSummaries. A 0 in column 4 or 5 signifies
   no support for that particular keying protocol. It is not the case
   that the number of implementations supporting SDES and DTLS-SRTP add
   up to the number supporting SRTP; in some cases, implementations were
   using unspecified means to key the SRTP stream.

[1] Gurbani, V.K. and Kolesnikov, V., "Work in progress: A secure and
  lightweight scheme for media keying in the Session Initiation Protocol
  (SIP)," Proceedings of the 4th Annual ACM Conference on Principles,
  Systems and Applications of IP Telecommunications (IPTComm 2010),
  August 2-3, 2010, Munich, Germany.

Ciao,

- vijay
-- 
Vijay K. Gurbani, Bell Laboratories, Alcatel-Lucent
1960 Lucent Lane, Rm. 9C-533, Naperville, Illinois 60566 (USA)
Email: vkg@{alcatel-lucent.com,bell-labs.com,acm.org}
Web:   http://ect.bell-labs.com/who/vkg/