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revision 1.199 by hemppah, Thu Mar 27 10:13:04 2003 UTC revision 1.200 by hemppah, Thu Mar 27 14:20:37 2003 UTC
# Line 1668  In this section, we will give a brief ov Line 1668  In this section, we will give a brief ov
1668  from recent publications. For general discussion about Fenfire in Peer-to-Peer environment,  from recent publications. For general discussion about Fenfire in Peer-to-Peer environment,
1669  see \cite{lukka02freenetguids}, and for detailed Storm design, see \cite{fallenstein03storm}.  see \cite{lukka02freenetguids}, and for detailed Storm design, see \cite{fallenstein03storm}.
1670    
1671  Storm (for \emph{STORage Module}) stores all data as data \emph{blocks}, which  Storm (for \emph{STORage Module}) stores all data as \emph{blocks}, which
1672  are immutable byte sequences. Storm \emph{assigns} a globally unique identifier to each  are immutable byte sequences. Storm \emph{assigns} a globally unique identifier to each
1673  data block\footnote{This resembles the process how tightly structured overlay assigns a subset of keys  block\footnote{This resembles the process how tightly structured overlay assigns a subset of keys
1674  to each participating peer: a user has no control over the assignment process.}. SHA-1 cryptographic  to each participating peer: a user has no control over the assignment process.}. SHA-1 cryptographic
1675  content hash function\footnote{SHA-1 is  content hash function\footnote{SHA-1 is
1676  considered as a collision free hash function. Therefore, it is very unlikely that two different Storm data blocks  considered as a collision free hash function. Therefore, it is very unlikely that two different Storm blocks
1677  would have same identifier.} \cite{fips-sha-1} is used  would have same identifier.} \cite{fips-sha-1} is used
1678  for creating unstructured and semantic-free, globally unique identifiers for blocks. Because of SHA-1  for creating unstructured and semantic-free, globally unique identifiers for blocks. Because of SHA-1
1679  content hash, all identifiers are directly the data verifiers as well. The uniqueness of blocks creates  content hash, all identifiers are directly the data verifiers as well. The uniqueness of blocks creates
# Line 1688  paper, however, we discuss only pointers Line 1688  paper, however, we discuss only pointers
1688  More information about diffs can be found from \cite{fallenstein03storm}.  More information about diffs can be found from \cite{fallenstein03storm}.
1689    
1690  \emph{Pointer} \cite{benja02urn5, fallenstein03storm} is a semantic-free updatable reference to  \emph{Pointer} \cite{benja02urn5, fallenstein03storm} is a semantic-free updatable reference to
1691  Storm data block. Pointer is a unique reference to the data and it is usually  Storm block. Pointer is a unique reference to the data and it is usually
1692  represented as a random string. Storm pointers are rather a \emph{concept} of data (e.g., ''The front page of the most recent  represented as a random string. Storm pointers are rather a \emph{concept} of data (e.g., ''The front page of the most recent
1693  version of New York Times newspaper'') whereas blocks \emph{contain} the data  version of New York Times newspaper'') whereas blocks \emph{contain} the data
1694  (''New York Times newspaper, 10.10.2002, version 1.0'').  (''New York Times newspaper, 10.10.2002, version 1.0'').
# Line 1760  file'', in which parts of the document a Line 1760  file'', in which parts of the document a
1760  \emph{global} data repository\footnote{Global repository is not a requirement. Locally constructed xanalogical  \emph{global} data repository\footnote{Global repository is not a requirement. Locally constructed xanalogical
1761  documents are feasible and they can be assembled without global data repository.}. System implementing the xanalogical storage model \emph{must}  documents are feasible and they can be assembled without global data repository.}. System implementing the xanalogical storage model \emph{must}
1762  support global scale data lookups, i.e., if a data item exists in the system it can be located and fetched.  support global scale data lookups, i.e., if a data item exists in the system it can be located and fetched.
1763  Specifically, our task is to locate and fetch (i.e., obtain) all Storm blocks\footnote{We call these blocks as \emph{scroll} blocks.},  Specifically, our task is to locate and fetch (i.e., obtain) all Storm blocks,
1764  associated to a specific ''virtual file'' from the Peer-to-Peer network. Also, in addition to the  associated to a specific ''virtual file'' from the Peer-to-Peer network\footnote{We call''associated'' blocks as \emph{scroll} blocks.}. Also, in addition to the
1765  \emph{direct} block obtaining using globally unique identifier of Storm block,  \emph{direct} block obtaining using globally unique identifier of Storm block,
1766  we also must support the \emph{indirect} obtaining of Storm block using the pointer mechanism.  we also must support the \emph{indirect} obtaining of Storm block using the pointer mechanism.
1767  Second, we want that users' operations in Fenfire  Second, we want that users' operations in Fenfire

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