Insecure Cipher Suite
- IANA name:
- TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA
- Hex code:
- 0x00, 0x0B
- TLS Version(s):
- TLS1.0, TLS1.1
- Protocol:
- Export-grade Transport Layer Security (TLS EXPORT)
- Key Exchange:
- Diffie-Hellman (DH)
- Authentication
- Digital Signature Standard (DSS)
- Encryption:
- Data Encryption Standard with 40bit key in Cipher Block Chaining mode (DES40 CBC)
- Hash:
- Secure Hash Algorithm 1 (SHA)
- Included in RFC:
- Machine-readable:
- application/json
Export ciphers used to be legally exportable from the United States of America in the 1990s, when exporting military technology was heavily restricted. Nowadays, they are considered insecure (cf. FREAK Attack).
Diffie-Hellman key exchanges not using ephemeral keys do not support Perfect Forward Secrecy (PFS) which is recommended, so attackers cannot decrypt the whole communication stream.
The CBC mode is vulnerable to plain-text attacks with TLS 1.0, SSL 3.0 and lower. However a real fix is implemented with TLS 1.2 in which the GCM mode was introduced and which is not vulnerable to the BEAST attack. GCM should be preferred over CBC (cf. BEAST).
DES is considered weak, primarily due to its short key-lengths of 40 or 65-Bit. Furthermore, it has been withdrawn as a standard by the National Institute of Standards and Technology in 2005.
The Secure Hash Algorithm 1 has been proven to be insecure as of 2017 (cf. shattered.io).