PaaSword: A Holistic Data Privacy and Security by Design Framework for Cloud Services

PaaSword: A Holistic Data Privacy and Security by Design Framework for Cloud Services

Yiannis Verginadis, Antonis Michalas, Panagiotis Gouvas, Gunther Schiefer, Gerald Hubsch, Iraklis Paraskakis

CLOSER 2015, Lisbon, May 21, 2015

Information Management Unit / ICCS of NTUA www.imu.iccs.gr

Agenda

Introduction

Data Security Challenges in the Cloud

PaaSword Framework

Conclusions


Introduction

Many users have started relying on cloud services without realizing it Many companies have remained cautious due to security concerns

Applications and storage volumes often reside next to potentially hostile virtual environments, leaving sensitive information at risk to theft, unauthorized exposure or malicious manipulation

Governmental regulation presents an additional concern of significant legal and financial consequences if data confidentiality is breached

Focused interest Experimentation Near ubiquitous use C

loud A

dopti

on


Related Work

Commonly used access control models (Ferrari 2010) are: Mandatory Access Control (MAC) Discretionary Access Control (DAC) Role-Based Access Control (RBAC)

Extending these models: location-aware access control (LAAC) - there is a clear lack of

supporting additional pertinent contextual information (Cleeff et al.,2010)

context-aware access control (CAAC) – with shortcomings like: lack of support for dynamically generated context (Covington et al., 2001) lack of fine-grained data access control (Kayes et al., 2013)


Related Work (contd.)

Regarding the policy management there is lack of proper separation of concerns (Kourtesis and Paraskakis, 2012) The policy definition and policy enforcement are entangled in the

implementation of a single software component, leading to the lack of portability explicit representation of policy relationships

Regarding the data distribution and encryption algorithms... Gentry (2009), introduced the first fully homomorphic encryption

scheme that enables semantically secure outsourcing to the cloud but presents severe performance issues

In CryptDB (Popa et al., 2011), the concept of onions was used with the main drawback the lack of security guarantees to the client


Agenda

Introduction


PaaSword Framework

Conclusions


Security Challenges in the Cloud

Top four threats identified (CSA, 2013) are: data leakage data loss account hijacking insecure APIs

The most critical part of a modern cloud application is the data persistency layer and the database itself

The OWASP foundation has categorized the database-related attacks as the most critical ones SQL injections represents 17% of all security breaches examined These attacks were responsible for 83% of the total records stolen,

from 2005 to 2011


Security Challenges in the Cloud (contd.)

Most of the security fences that are configured in a corporate environment target the fortification of the so-called network perimeter e.g. routers, hosts and virtual machines

IDS and IPS try to cope with database-takeover security aspects, but the risk of database compromise is greater than ever, as: automated exploitation tools (e.g. SQLMap) are widely spread IPS and IDS evasion techniques have become extremely sophisticated

Internal adversaries or even unknown vulnerabilities of software platforms widely adopted in the cloud may provide malicious access to sensitive data e.g. Heartbleed flaw - constituted a serious fault in the OpenSSL

cryptography library, which remained unnoticed for more than two years and affected over 60% of Web servers worldwide


Security Challenges in the Cloud (contd.)

Regarding the post-exploitation phase things are even worse in the case where a symmetric encryption algorithm has been employed cracking toolkits that utilize GPU processing power (e.g. oclHashcat) are able to

crack ciphers using brute-force techniques with an attack rate of 162 billion attempts per second

The application developer is the one responsible for both sanitizing all HTTP-input parameters reassuring that compromised data will be useless

Nevertheless, the mere utilization of an IaaS or PaaS provider, may by itself spawn a multitude of inherent vulnerabilities that cannot be tackled effectively as they typically exceed the

responsibilities of an application developer


Agenda

Introduction


PaaSword Framework

Conclusions


Threat Model

We assume a semi-honest adversarial model for the cloud provider (Paladi et al., 2014; Santos et al., 2009) a malicious cloud provider correctly follows the protocol specification

but can intercept all messages and may attempt to use them in order to learn information that otherwise should remain private

For the rest of the participants we consider the threat model (Santos et al., 2009) that assumes that privileged access rights can be used by a remote adversary, ADV, to leak confidential information e.g. a corrupted system administrator, can obtain remote access to any

host maintained by the provider. the adversary cannot access the volatile memory of any guest virtual

machine (VM) residing on the compute hosts of the provider


Context-aware Access Model

We envision a XACML-based context-aware access model, which is needed by the developers in order to annotate the Data Access

Objects of their applications


Facets of the Context-Aware Access Model

Facets

IP Address

(Local)Time

Location DeviceType

Data Connection

Type

etc…

Patterns

Frequency UsualDuration

UsualDates

UsualHours

PreviouslyAccessed

Data

Sensitive / Non Sensitive Data

Role


Policies Access, Governance and Enforcement

A middleware that will provide: a transparent key usage for efficient authentication purposes, annotation capabilities in the form of a tool (IDE plugin) for allowing

developers to declaratively create the minimum amount of rule-set that is needed for security enforcement purposes

dynamically interpret the DAO annotations into policy enforcement rules

the governance and quality control of the annotations and their respective policy rules

the formulation and implementation of the overall policy enforcement business logic


Devise an appropriate vocabulary of concepts and decide how they are interrelated

Populate the framework with appropriate instances to give rise to DAOs

Formalise these concepts and their interrelations – gives rise to the ontology framework

Ontology for Access Policies


Secure Storage

We propose a design for a cryptographic cloud storage that will be based on a symmetric searchable encryption (SSE) scheme similar to (Kamara and Lauter, 2010)

We plan to extend the previous work Cumulus4j (Huber et al., 2013) and MimoSecco (Gabel and Hubsch, 2014)) that hides relations between different data values of a data row


PaaSword High-level View


Conceptual Architecture


Agenda

Introduction


PaaSword Framework

Conclusions


Conclusions & Next Steps

Future work involves the implementation of the proposed framework This solution will be validated through 5 pilots:

Encrypted persistency as a service in a PaaS provider Intergovernmental secure document and personal data exchange Secure sensors data fusion and analytics Protection of personal data in a multi-tenant CRM Protection of sensible enterprise information in multi-tenant ERP

Thank you for listening!

Acknowledgements:This work is related to the PaaSword project and

has received funding from the European Union’s Horizon 2020 research and innovation programme under grant

agreement No 644814

PaaSword: A Holistic Data Privacy and Security by Design Framework for Cloud Services

Technology

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