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HTTP500_195339's avatar
HTTP500_195339
Icon for Nimbostratus rankNimbostratus
Apr 02, 2015

DES-CBC3-SHA listed as 192 bits but SSL Labs reports as 112 bit

In the table here under the BIG-IP 11.5.0 - 11.5.2 section it lists the DES-CBC3-SHA ciphers as 192 bits.   However a SSL Labs scan will report the following:   TLS_RSA_WITH_3DES_EDE_CBC_SHA (0...
11.5.1
ciphers
tls_rsa_with_3des_ede_cbc_sha
amolari's avatar
amolari
Icon for Cirrus rankCirrus
Apr 09, 2015

there was a thread about that here

 

It seems to be a "bug".. 192 comes from 3x64 (64 is the block size).

 

If in theory it's 168 bits key length, it has been degraded to 112 due to vulnerabilities.

 

From NIST 800-57:

 

"One might expect that 3TDEA would provide 56×3 = 168 bits of strength. However, there is an attack on 3TDEA that reduces the strength to the work that would be involved in exhausting a 112 bit key"