Cryptanalysis of the Full Spritz Stream Cipher

@article{Banik2016CryptanalysisOT,
  title={Cryptanalysis of the Full Spritz Stream Cipher},
  author={Subhadeep Banik and Takanori Isobe},
  journal={IACR Cryptol. ePrint Arch.},
  year={2016},
  volume={2016},
  pages={92}
}
Spritz is a stream cipher proposed by Rivest and Schuldt at the rump session of CRYPTO 2014. It is intended to be a replacement of the popular RC4 stream cipher. In this paper we propose distinguishing attacks on the full Spritz, based on a short-term bias in the first two bytes of a keystream and a long-term bias in the first two bytes of every cycle of N keystream bytes, where N is the size of the internal permutation. Our attacks are able to distinguish a keystream of the full Spritz from a… 

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References

SHOWING 1-10 OF 26 REFERENCES

Spritz - a spongy RC4-like stream cipher and hash function

This note reconsiders the design of the stream cipher RC4, and proposes an improved variant, which is called Spritz (since the output comes in ne drops rather than big blocks), which can be easily adapted for use as a cryptographic hash function, an encryption algorithm, or a message-authentication code generator.

Full Plaintext Recovery Attack on Broadcast RC4

Several new biases in the initial (1st to 257th) bytes of the RC4 keystream, which are substantially stronger than known biases are introduced, which enable a plaintext recovery attack using a strong bias set of initial bytes.

New State Recovery Attack on RC4

A state recovery attack which accepts the keystream of a certain length, and recovers the internal state, and it is much smaller than the complexity of the best known previous attack 2779.

State-Recovery Analysis of Spritz

The analysis supports the conjecture that compared to RC4, Spritz may also provide higher resistance against potentially devastating state-recovery attacks and introduces three different state recovery algorithms.

Security Analysis of the RC4+ Stream Cipher

It is shown that that the RC4+ is vulnerable to differential fault attack and it is possible to recover the entire internal state of the cipher at the beginning of the PRGA by injecting around 217.2 faults.

Some security results of the RC4+ stream cipher

Surprisingly, it is found that if the value of the pad is made equal to 0x03, the design provides maximum resistance to distinguishing attacks, and the differential fault attack on RC4+ is improved, both in terms of number of faults required and the computational complexity.

A New Weakness in the RC4 Keystream Generator and an Approach to Improve the Security of the Cipher

A new pseudorandom bit generator, named RC4A, which is based on RC4’s exchange shuffle model is proposed, and it is shown that the new cipher offers increased resistance against most attacks that apply to RC4.

Quad-RC4: Merging Four RC4 States towards a 32-bit Stream Cipher

This paper keeps the basic RC4 structure and combines 4 RC4 states tacitly to design a high throughput stream cipher called Quad-RC4 that produces 32- bit output at every round and is comparable with HC-128, the fastest software stream cipher amongst the eSTREAM nalists.

A Distinguishing Attack on a Fast Software-Implemented RC4-Like Stream Cipher

A considerable bias is found in the output sequence of the RC4-like stream cipher and this bias is used along with the first two words of a keystream associated with approximately 230 secret keys to build a distinguisher.

Towards a General RC4-Like Keystream Generator

This paper proposes a new 32/64-bit RC4-like keystream generator that produces 32 or 64 bits in each iteration and can be implemented in software with reasonable memory requirements and can resist attacks that are successful on the original RC4.