Paper 2006/341

MV3: A new word based stream cipher using rapid mixing and revolving buffers

Nathan Keller, Stephen D. Miller, Ilya Mironov, and Ramarathnam Venkatesan


MV3 is a new word based stream cipher for encrypting long streams of data. A direct adaptation of a byte based cipher such as RC4 into a 32- or 64-bit word version will obviously need vast amounts of memory. This scaling issue necessitates a look for new components and principles, as well as mathematical analysis to justify their use. Our approach, like RC4's, is based on rapidly mixing random walks on directed graphs (that is, walks which reach a random state quickly, from any starting point). We begin with some well understood walks, and then introduce nonlinearity in their steps in order to improve security and show long term statistical correlations are negligible. To minimize the short term correlations, as well as to deter attacks using equations involving successive outputs, we provide a method for sequencing the outputs derived from the walk using three revolving buffers. The cipher is fast --- it runs at a speed of less than 5 cycles per byte on a Pentium IV processor. A word based cipher needs to output more bits per step, which exposes more correlations for attacks. Moreover we seek simplicity of construction and transparent analysis. To meet these requirements, we use a larger state and claim security corresponding to only a fraction of it. Our design is for an adequately secure word-based cipher; our very preliminary estimate puts the security close to exhaustive search for keys of size < 256 bits.

Available format(s)
Cryptographic protocols
Publication info
Published elsewhere. This is the full version of a paper to appear in CT-RSA 2007 (about 9 pages longer, with appendices)
stream cipherrandom walksexpander graphcryptanalysis
Contact author(s)
miller @ math rutgers edu
2006-10-20: received
Short URL
Creative Commons Attribution


      author = {Nathan Keller and Stephen D.  Miller and Ilya Mironov and Ramarathnam Venkatesan},
      title = {MV3: A new word based stream cipher using rapid mixing and revolving buffers},
      howpublished = {Cryptology ePrint Archive, Paper 2006/341},
      year = {2006},
      note = {\url{}},
      url = {}
Note: In order to protect the privacy of readers, does not use cookies or embedded third party content.