21.02.2012: PKI is dead -- according to Prof. Bungartz

Today, and tomorrow, the traditional DFN Cert workshop Security takes place in Hamburg [1]. The most striking result of that workshop was the official claim, that PKI is dead.

Prof. Bungartz is head of the DFN 'Verein' [2] and based his profound thesis on the fact that one can buy now X.509 (intermediate) root certificates for man-in-the-middle attacks -- which became public known recently [3]. This situation is different from the filtering of SSL/TLS traffic through eg. BlueCoat appliances at the company's periphery, since this requires to insert specific valid CA certs into to Web browser of the company's clients.

Now, with the new CA certs, you can simply attack any client and decrypt it's traffic even with full qualified (golden) root CA certs at the client's side since the CA verification chain is broken. In addition with the known 'stolen' CA certs [4] (you could put on a CRL [5]) the entire public PKI is now compromised. Any attempt, to verify CA certs by means of OCSP [6] becomes obsolete. Even Google discusses [7] not to depend on this information anymore.

Actually, this leads to the paradox result, that self-signed X.509 certificate become more trustworthy than public certs; simply because any verification mechanism is compromised.


[1] http://www.dfn-cert.de/veranstaltungen/workshop.html
[2] http://idw-online.de/de/news454390
[3] http://www.h-online.com/security/news/item/Trustwave-issued-a-man-in-the-middle-certificate-1429982.html
[4] http://www.h-online.com/security/news/item/CA-hack-more-bogus-certificates-1334651.html
[5] http://en.wikipedia.org/wiki/Certificate_revocation_list
[6] http://en.wikipedia.org/wiki/OCSP
[7] http://www.h-online.com/security/news/item/Google-wants-to-do-away-with-online-certificate-checks-1429487.html