Mittlerweile unterstützen ING-DIBA und DAB-Bank die NSA-sichere TLS-Variante "Perfect Forward Secrecy". Das Online-Banking der Postbank jedoch noch nicht.

openssl s_client -cipher 'ECDH:DH' -connect banking.postbank.de:443

CONNECTED(00000003)
140331701937824:error:14077410:SSL routines:SSL23_GET_SERVER_HELLO:sslv3 alert handshake failure:s23_clnt.c:762:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 7 bytes and written 319 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
---