what-when-how
In Depth Tutorials and Information
c.
u
relays this request to the trusted identification service based on the DHT;
d. the trusted identification service derives node's pseudonym P
v
=
h
1
(
N
)
and its node identifier
v
=
h
1
(
N
) from node's properties
N
=
(
h
1
,
h
2
are two cryptographic hash functions). It also grants two certificates
{
I
+
, }
v
S
TTP
and
{
P
+
P
,
}
, where
S
TTP
is the signature of the identifica-
v S
TTP
tion service;
e. once
u
receives the response from the identification, it will relay the response
to
v
.
(Step 2) Joining the P2P substrate:
According to the received certifications,
v
joins the P2P substrate using
u
as a boot-
strapping host and P
v
as its pseudonym.
(Step 3) Creation of the profile:
v
can independently generate its profile consisting of several attributes for each
entry, and generates public key pairs, which it signs with
I
+
, for each attribute
in order to share it with preferred users. hen each attribute is encrypted with its
respective private key. he friend list is an important attribute in Reference 8,
v
retrieves the name attribute from its contacts like
u
in their encrypted form and lists
these as the friend list, inally encrypted with its own respective key. hus, a user
is able to access the profile only if it is admitted by the nodes in the chain from the
outmost to the innermost ring in the matryoshka.
(Step 4) Matryoshka creation:
Figure 10.8 illustrates the process of matryoshka creation for
v
. Initially,
v
only
knows
u
. Step 4 further includes the following smaller steps:
a.
v
stores its encrypted profile in
u
;
b. It sends a request to register to DHT and a time-to-live counter,
ttl
, to
u
;
E M ttl
u
{
,
}
with
M
=
{ ,
k v
,
Ρ
,{
I
+
, }
v
}
where
k
is the lookup key
P
vu
vu
u
v
S
S
TTP
I
v
for the DHT;
c. Once
u
receives the message from
v
, it selects a node from its contact list arbi-
trarily, for example,
w,
and encapsulates
M
vu
, then sends it together with the
decreased
ttl
counter
ttl
'
to
w
:
E M ttl
{
,
'}
P
uw
w
=
Ρ Ρ
Ρ
with
M
{ ,
k
,
,{
P
+
,
}
,
M
}
;
uw
u
w
u
u S
vu S
TTP
P
u
d. repeat (c) recursively until the
ttl
expires (
ttl
is set according to the require-
ment of the number of the rings in a matryoshka).
e. Once the message reaches the outermost ring, the node will register the key
and authenticate it according to the chain of encapsulated signatures.
