What Does RC4 Mean?

RC4 is a symmetric key cipher and bite-oriented algorithm that encrypts PC and laptop files and disks as well as protects confidential data messages sent to and from secure websites. Output bytes require eight to 16 operations per byte. It is a stream cipher.


Techopedia Explains RC4

RC4 can only be used one time to maintain its cryptographic security strength. Even so, it is considered very secure. RC4 was first designed by Rivest for RSA Security. A random number generator, also called a state machine, and each state transmission is outputted one bit of information at a time.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.