Editing Symmetric-key algorithm (section)

== Key generation ==
{{ main | key generation }}
When used with asymmetric ciphers for key transfer, [[Cryptographically secure pseudorandom number generator|pseudorandom key generator]]s are nearly always used to generate the symmetric cipher session keys. However, lack of randomness in those generators or in their [[initialization vector]]s is disastrous and has led to cryptanalytic breaks in the past. Therefore, it is essential that an implementation use a source of high [[Entropy (information theory)|entropy]] for its initialization.<ref>
Ian Goldberg and David Wagner.
[http://www.cs.berkeley.edu/~daw/papers/ddj-netscape.html "Randomness and the Netscape Browser"].
January 1996 Dr. Dobb's Journal.
quote:
"it is vital that the secret keys be generated from an unpredictable random-number source."
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{{cite web |first1=Thomas |last1=Ristenpart |first2=Scott |last2=Yilek |title=When Good Randomness Goes Bad: Virtual Machine Reset Vulnerabilities and Hedging Deployed Cryptography |date=2010 |work=NDSS Symposium 2010 |url=https://www.ndss-symposium.org/wp-content/uploads/2017/09/rist.pdf |quote=Random number generators (RNGs) are consistently a weak link in the secure use of cryptography.}}
</ref><ref>{{cite web |url = http://www.webhosting.uk.com/blog/symmetric-cryptography/ |title = Symmetric Cryptography |publisher = James |date = 2006-03-11 }}</ref>