what-when-how
In Depth Tutorials and Information
according to the same rules. Besides, it is not necessary for the nodes on the same
ring to trust each other, except for the first ring. Under certain encryption opera-
tions, the information of the core node is made copies on all the nodes in the first
ring. hus, the messages go through the concentric rings from an outermost node
to an innermost node. Every node must establish its matryoshka once it enters the
system and keep updating it. he privacy is preserved based on the hop-by-hop
trust relationships.
10.3.2 Peer-To-Peer Substrate
According to users' identifiers, the peer-to-peer substrate provides the global access
to its data. Each node in the peer-to-peer substrate is arranged in a distribute hash
table (DHT) associating with the distributed systems. he pseudonym of each
node is used to identify its location in the DHT according to the DHT protocol.
hus, the location data include the pointers to nodes on the outermost ring of the
requested user's matryoshka. he node in peer-to-peer substrate works as an entry
to access the information of the target node.
10.3.3 Trusted Identification Service
Each node gets a unique pseudonym, a unique node identifier, and two certificates
for the authentication for each type of identifiers from the trusted identification ser-
vice. he pseudonym is used as an identiier in the peer-to-peer system, and the node
identifier is used to identify a member of the STN. Such mechanism leads to the
protection of Sybil attacks, impersonation attacks, and attacks on the DHT overlay.
Reference 8 uses a straightforward public key cryptography in order to realize
the privacy preservation. Each node has a set of properties
N
such as the pseud-
onym and the node identifier. It generates two key pairs:
I
and
P
. he identiication
service certifies the authenticity of
I
and
P
to encrypt the pseudonym P and the
node identiier respectively. he relationship among
I
,
P
and P cannot be inferred,
except for the trusted nodes of a user.
he system proposed in Reference 8 provides the following six operations in
order to realize the service required in the network:
10.3.3.1 Account Creation
An account is created by an invitation initiated from a user
u
to a different user
v
(
u
is a user already existing in the system;
v
is denoted as a user who wants to take
part in the system.). here are four steps for account creation:
(Step 1) Identity creation: It has the following smaller steps:
a.
v
creates the two key pairs
I
and
P
;
b.
v
sends a request to
u
for obtaining pseudonym, node identifier, and
certificates;
