Is RC4 A stream cipher?
RC4 (also known as Rivest Cipher 4) is a form of stream cipher. It encrypts messages one byte at a time via an algorithm. Plenty of stream ciphers exist, but RC4 is among the most popular.
How does RC4 stream cipher work?
RC4 generates a pseudo-random stream of bits (a key-stream). As with any stream cipher, these can be used for encryption by combining it with the plaintext using bit-wise exclusive-or. Decryption is performed the same way (since exclusive-or is a symmetric operation). Two 8-bit index-pointers (denoted “i” and “j”).
What is RC4 cipher used for?
RC4 is one of the most commonly used stream ciphers, having been used in Secure Socket Layer (SSL)/ Transport Layer Security (TLS) protocols, IEEE 802.11 wireless LAN standard, and the Wi-Fi Security Protocol WEP (Wireless Equivalent Protocol).
What is the security concept behind the RC4?
RC4 means Rivest Cipher 4 invented by Ron Rivest in 1987 for RSA Security. It is a Stream Ciphers. Stream Ciphers operate on a stream of data byte by byte. RC4 stream cipher is one of the most widely used stream ciphers because of its simplicity and speed of operation.
Is RC4 used today?
This led to an increase in the number of websites using RC4 (approximately 50%) but it has now dropped back and, according to the Computer Science Institute at University of California at Berkeley, approximately 13% of sites worldwide still use RC4.
Is IV same as nonce?
IV and nonce are often used interchangeably. Essentially though, an IV is a nonce with an additional requirement: it must be selected in a non-predictable way. This would eliminate all sequential nonces, an IV must be random.
Why is RC4 not used?
Unfortunately, people don’t use RC4 because they know what a MAC is — they use RC4 because you can download the code from Wikipedia. So, again, while this can happen with many ciphers, it tends to happen with RC4 a lot more than it should.
Does IV need to be secret?
IV usually does not need to be secret, However, in most cases, it is important that an initialization vector is never reused under the same key. Wikipedia: An initialization vector has different security requirements than a key, so the IV usually does not need to be secret.
Why does IV need to be unique?
You should use random IV even when unique keys are used. This prevents key-collision attack where the attacker collects number of cryptograms that have been encrypted with unique keys and brute-forces for key.
What is RC4 encryption?
RC4 Encryption. RC4 is an encryption algorithm. It is used in WEP and WPA, which are encryption protocols commonly used on wireless routers and also in BitTorrent protocols encryption.
How does RC4 work?
RC4 generates a pseudorandom stream of bits (a keystream ). As with any stream cipher, these can be used for encryption by combining it with the plaintext using bit-wise exclusive-or; decryption is performed the same way (since exclusive-or with given data is an involution ).
What is stream encryption?
A stream cipher encrypts an arbitrary length of plain text, one bit at a time, with an algorithm that uses a key.