Insecure Cipher Suite

IANA name:

TLS_RSA_EXPORT_WITH_DES40_CBC_SHA

Hex code:

0x00, 0x08

TLS Version(s):

TLS1.0, TLS1.1

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Protocol:

Export-grade Transport Layer Security (TLS EXPORT)

Export-grade cipher suite:

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 (see freakattack.com).

Key Exchange:

Rivest Shamir Adleman algorithm (RSA)

Non-ephemeral Key Exchange:

This key exchange algorithm does not support Perfect Forward Secrecy (PFS) which is recommended, so attackers cannot decrypt the complete communication stream.

Authentication:

Rivest Shamir Adleman algorithm (RSA)

RSA Authentication:

There are reports that servers using the RSA authentication algorithm with keys longer than 3072-bit may experience heavy performance issues leading to connection timeouts and even service unavailability if many clients open simultaneous connections.

Encryption:

Data Encryption Standard with 40bit key in Cipher Block Chaining mode (DES40 CBC)

Cipher Block Chaining:

In 2013, researchers demonstrated a timing attack against several TLS implementations using the CBC encryption algorithm (see isg.rhul.ac.uk). Additionally, the CBC mode is vulnerable to plain-text attacks in TLS 1.0, SSL 3.0 and lower. A fix has been introduced with TLS 1.2 in form of the GCM mode which is not vulnerable to the BEAST attack. GCM should be preferred over CBC.

Data Encryption Standard:

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 Furthermore, it has been withdrawn as a standard by the National Institute of Standards and Technology in 2005.

Hash:

Secure Hash Algorithm 1 (SHA)

Secure Hash Algorithm 1:

The Secure Hash Algorithm 1 has been proven to be insecure as of 2017 (see shattered.io).

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Included in RFC:

• RFC 4346

Machine-readable:

application/json