Databases Reference
In-Depth Information
assurances
⊆
{query correctness, data confidentiality, access privacy}
1
Data Pre-
Processor
“outsourcing”
encrypted
2
Data
queries
plaintext
“
owner
”
3
query results,
assurances
Outsourced
Data
Query
Pre/Post-
Processing
Query Processor
data client(s!)
data server
(
un-trusted
)
M
allory
E
ve
Fig. 1.
Secure Data Outsourcing. Clients require assurances of correctness, confi-
dentiality and access privacy.
is a hard problem because in most cases decryption keys cannot be directly
provided to potentially untrusted database servers. Moreover, result complete-
ness and data integrity (i.e., correctness) become essential. Therefore, solu-
tions that do not address these dimensions are incomplete and insecure.
We will explore designs for outsourced relational data query mechanisms
that (i) ensure queries have been executed with
integrity and completeness
over their respective target data sets, (ii) allow queries to be executed with
confidentiality
over encrypted data, and (iii) guarantee the
privacy
of client
queries and data access patterns:
Correctness.
Clients should be able to verify the integrity and complete-
ness of any results the server returns. For example, when executing a JOIN
query, they should be able to verify that the server returned
all
matching
tuples.
Confidentiality.
The data being stored on the server should not be
decipherable either during transit between the client and the server, or at the
server side, even in the case when the server is malicious.
Access Privacy.
An intruder or a malicious server should not be able
to perform statistical attacks by exploiting query patterns. For example, it
should not be able to compromise data confidentiality by correlating known
public information with frequently queried data items.
We will discuss how to design protocols that adapt to the existence of
trusted hardware
— so critical functionality can be delegated securely from
clients to servers and increased assurance levels can be achieved more ef-
