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revision 1.64 by hemppah, Mon Feb 24 13:24:41 2003 UTC revision 1.65 by hemppah, Mon Feb 24 13:36:48 2003 UTC
# Line 1554  sequential and random access. This memo Line 1554  sequential and random access. This memo
1554     \cite{overneturl}     \cite{overneturl}
1555     \cite{edonkey2kurl}     \cite{edonkey2kurl}
1556        
1557     \cite{bittorrenturl}  
 \cite{maymounkov03ratelesscodes}  
1558    
1559  \section{Overview}  \section{Overview}
1560    
# Line 1645  scalable, efficient, adaptive, robust, s Line 1644  scalable, efficient, adaptive, robust, s
1644  attacks. Additionally, if possible, it would be benefitial if Peer-to-Peer system  attacks. Additionally, if possible, it would be benefitial if Peer-to-Peer system
1645  would represent all named resources as keys.  would represent all named resources as keys.
1646    
 \section{Benefits over existing Peer-to-Peer file sharing systems}  
   
1647  Since Storm uses SHA-1 hash function for creating globally unique  Since Storm uses SHA-1 hash function for creating globally unique
1648  identifiers, if necessary, we can check the integrity of a scroll  identifiers, if necessary, we can check the integrity of a scroll
1649  block by re-computing hash value for a scroll block, once fetched  block by re-computing hash value for a scroll block, once fetched
1650  form the network. Indeed, all scroll blocks' identifiers are  form the network. Indeed, all scroll blocks' identifiers are
1651  self-certifying. However, this not very efficient when we want  self-certifying. However, this not very efficient if we want to
1652  fetch large amounts of data. One possibility is to use tree-based  obtain large amounts of data. One possibility is to use tree-based
1653  hash techiques (e.g., \cite{merkle87hashtree}, \cite{\cite{mohr02thex})  hash techiques (e.g., \cite{merkle87hashtree}, \cite{\cite{mohr02thex}),
1654  for more efficient data fetcing. Tree based hash functions can be used  which makes possible multisource downloads. Tree based hash functions can be used
1655  to verify fixed length segments of data file, instead of whole data file.  to verify fixed length segments of data file, instead of whole data file.
1656  Currently, Shareaza \cite{shareazaurl}, Overnet \cite{overneturl} and  Currently, Shareaza \cite{shareazaurl}, Overnet \cite{overneturl} and
1657  eDonkey2000 \cite{edonkey2kurl} uses tree based hashing for validating  eDonkey2000 \cite{edonkey2kurl} uses tree based hashing for validating
1658  segments of a data file.  segments of a data file. Another options for more efficient data
1659    fething is use multisource downloading (\cite{bittorrenturl}) and online
1660    codes (\cite{maymounkov03ratelesscodes}).
1661  - Easy syncing:  
1662    - Just copy a bunch of blocks  Multisource downloads can be very useful when video, images or sound
1663    %- Documents can be synced & merged  is stored using Storm storage model. However, further research is
1664    %- Inter-document structures can be synced & merged  required.
   - Syncing can be done without merging immediately,  
     leaving two alternative versions current  
     (so e.g. an automated process is entirely possible,  
     even when there are conflicts)  
 - Versioning  
   
 From Benja's (plus antont and me) article:  
 - Reliability (old versions, links work always, accessibility, append-and-delete)  
 - Usability in the face of intermittent connectivity  
   (includes syncing, finding a document if available...)    
 - Xanalogical structure  
   (includes versioning, non-breaking links etc.)  
   
 -current p2p systems don't support all of these properties together  
1665    
1666    For more detailed discussion about Storm's storage model, see
1667    \cite{fallenstein03storm}.
1668    
1669  \section{Evaluation}  \section{Evaluation}
1670    

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