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try at large and only after several years of testing have they been named as algorithms it for use to
protect sensitive and classiied information.
Several application vendors also claim that their application employs a “proprietary encryption
methodology” that is too secret to reveal and insist that is quite fortiied against any attacks. It is
advisable for organizations and individuals to stay away from such claims, if they are serious about
protecting their sensitive information, because as we have already seen, encryption algorithms are
most efective when their mechanism is open to the public domain. he only element of secret
in an encryption algorithm is the key. hese proprietary encryption algorithms usually consist of
simple substitution and transposition of data protected, which is untested and unattested by any
organization, governmental or otherwise.
8.2.3.2 Weak Ciphers
We have discussed, during the course of the chapter, encryption keys and hash functions being
broken. Once an algorithm is broken by some of the cryptographic attacks, especially the brute-
force attack, it is considered broken; ergo, it is unsafe for use in a commercial environment to
protect sensitive information. However, in several situations, weak ciphers continue to be used by
Web application developers, unaware of the potential danger of continued use of the encryption
algorithm or hash function. he most important example of this would be the MD5, which is still
a very popular hash functions used for protection of user passwords and also used extensively for
SSL certiicates to provide message integrity. he MD5 has been proven insecure and has been
broken by collision attacks performed against it. Another classic instance of a weak algorithm
would be the use of the RC4, a lavor of which is still used to protect wireless networks with the
WEP. he WEP has been labeled as a nonsecure wireless network implementation, and users have
been encouraged to move on to WPA. Web application developers should take cognizance of the
fact that weak algorithms like DES, MD5, RC4, and SHA-1 should not be used in mission-critical
Web applications processing and storing sensitive information.
8.2.3.3 Insecure Implementation of Strong Ciphers
Encryption of data using strong ciphers is usually the easier part of the implementation of
cryptography in protecting sensitive information. he tougher part is to maintain conidenti-
ality of the key and the encrypted data after it is stored in a ile or database. Key management
is one of the most important but oft-ignored aspects of cryptography. his is so at the organi-
zation's peril. Key management includes the secure generation, storage, transport, revocation,
and replacement of keys. Keys are the most secret aspect of any cryptosystem, and weak keys
based on easily guessable passwords or pass phrases are often used as keys to protect data. Keys
are transported as unencrypted network traic, thereby making it opportune for an attacker
to snif the traic and make hay with the key. Keys are also stored in the most improper
locations and in a nonsecure manner, ensuring that any conidentiality provided to the data
encrypted with even the strongest of encryption algorithms is rendered useless because of inef-
fective key management.
8.2.3.4 Weak or Nonexistent Transport Layer Security
An organization interested in protecting data at rest cannot aford to ignore transport layer secu-
rity. Transport layer security is the process of encrypting data in transit. One of the best practices
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