Insecure Cipher Suite

IANA name:

TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5

Hex code:

0x00, 0x06

TLS Version(s):

TLS1.0, TLS1.1, TLS1.2

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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:

Rivest Cipher 2 with 40bit key in Cipher Block Chaining mode (RC2 CBC 40)

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.

Rivest Cipher 2:

There exists a related-key attack found in 1997. With this attack, RC2 can be broken (see schneier.com).

Hash:

Message Digest 5 (MD5)

Message Digest 5:

The Message Digest 5 algorithm suffers form multiple vulnerabilities and is considered insecure.

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Included in RFC:

• RFC 4346

Machine-readable:

application/json