Sakti, Lintang Sandy Tria () IMPLEMENTASI ALGORITMA RC4 UNTUK ENKRIPSI-DEKRIPSI PADA APLIKASI SMS. Other thesis. Abstract. Security and confidentiality of data is currently a very important issue and continues to grow. Some cases involving data security is. sebab itu muncul ide membuat sistem keamanan data dengan algoritma kriptografi mengimplementasikan algoritma RC4 dan CBC untuk merahasiakan data.

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If not used together with a strong message authentication code MACthen encryption is vulnerable to a bit-flipping attack.

Enkripsi Data Menggunakan Algoritma RC4

The design of RC4 avoids the use of LFSRs and is ideal for software implementation, as it requires only byte manipulations. Archived from the original on 22 July RC4 was initially a trade secretbut in September a description of it was anonymously posted to the Cypherpunks mailing list. The keystream generated by the RC4 algpritma biased in varying degrees towards certain sequences making it vulnerable to distinguishing attacks. So after iterations of this inner loop, the value i incremented by w every iteration has taken on all possible values Abstract Nowdays, Short Message Service is one algroitma popular way to communicate.

Scott Fluhrer and David McGrew also showed such attacks which distinguished the keystream of the RC4 from a random stream given a gigabyte of output. Like other sponge functionsSpritz can be used to build a cryptographic hash function, a deterministic random bit generator DRBGan encryption algorithm that supports authenticated encryption with associated data AEADetc.

Ina new and surprising discovery was made by FluhrerMantin and Shamir: As mentioned above, the most important weakness of RC4 comes from the insufficient key schedule; the first bytes of output reveal information about the key. In this rcc4, there are modifications to the Diffie-Hellman protocol that is the calculation of the public key and symmetric key to include cellular phone number as authentication. Retrieved 26 October Email the author Login required.


Whereas on alyoritma modified RC4 is the key where there is a combination with cellular rv4 number as authentication and key randomization, and then there are also modifications to the algoritja byte generator, encryption and decryption of the RC4 algorithm.

For other uses, algoritka RC4 disambiguation. One approach to addressing this is to generate a “fresh” RC4 key by hashing a long-term key with a nonce.

To generate the keystream, the cipher makes use of a secret internal state which consists of two parts:. Performing a modular reduction of some value modulo can be done with a bitwise AND with which is equivalent to taking the low-order byte of the value in question.

Enkripsi Data Menggunakan Algoritma RC4 – Politeknik Negeri Padang

This is due to the fact that if the third byte of the original state is zero, and the second byte is not equal to 2, then the second output byte is always zero. This research implements RC4 symmetric cryptography to encrypt and decrypt messages, while for key exchange is using Diffie-Hellman protocol. The leaked code was confirmed to be genuine as its output was found to match that of proprietary software using licensed RC4. RC4 algorithm is one of the type of stream cipher algorithm that can be used to encrypt the contents of the message.

In symmetric cryptography, there is a symmetric key for encryption and decryption process. Such bias can be detected by observing only bytes. Where a protocol is marked with ” optionally “, RC4 is one of multiple ciphers the system can be configured to use. Stream ciphers Broken stream ciphers Pseudorandom number generators Free ciphers.


Retrieved 6 January This caused a scramble for a standards-based replacement for WEP in the FSEpages —, vol. Views Read Edit View history. Email this article Login required. Spritz was broken by Banik and Isobe. This page was last edited on 30 Novemberat Once this has been completed, the stream of bits is generated using the pseudo-random generation algorithm PRGA. This article is about the stream cipher. The cipher is also vulnerable to a stream cipher attack if not implemented correctly.

InAndrew Roos experimentally observed that the first byte of the keystream is correlated to the first three bytes of the key and the first few bytes of the permutation after the KSA are correlated to some linear combination of the key bytes.

The permutation is initialized with a variable length keytypically between 40 and bits, using the key-scheduling algorithm Algorirma. Royal Holloway University of London. Although stronger than RC4, this algorithm has also been attacked, with Alexander Maximov [57] and a team from NEC [58] developing ways to distinguish its output from a truly random sequence.

The output generation function operates as follows:. Proposed new random number generators are often compared to the RC4 random number generator. For as many iterations as are needed, the PRGA modifies the state and outputs a byte of the keystream.

Many stream ciphers are based on linear-feedback shift registers LFSRswhich, while efficient in hardware, are less so in software.