backward and forward looking at dependable and secure computing

1INSTITUTE OF COMPUTING TECHNOLOGY CHINESE ACADEMY OF SCIENCESINSTITUTE OF COMPUTING TECHNOLOGY CHINESE ACADEMY OF SCIENCES

Backward and forward looking at dependable and secure computing

Yinghua Min

Fellow of IEEEInstitute of Computing Technology,

Chinese Academy of Sciences, Beijing, China

At PRDC09, 2009/11/16


Outline Historical review of dependable computing

FTCS DSN IFIP WG10.4 PRDC

New challenges of dependable and secure computing

Old techniques facing new environments Concentrated on practical problems, rather than

conceptual games


FTCS

Established in 1970 FTC for critical applications

Aviation Spaceflight Railway transportation

A highly academic symposium


Dependable computing

People understood that our area needed some extension.

A. Avizienis and Jean-Claude Laprie proposed the concept of Dependable Computing at FTCS-15 in 1985.

Human being is included in systems then. Malicious faults

FTCS DCCA

DSN in 2000


DSN

Since 2000 DSN has pioneered the fusion between

security and dependability. Understanding the need to

simultaneously fight against cyber attacks, accidental faults, design errors, and unexpected operating conditions.


PRDC

1989 Joint Symposium on Fault--Tolerant Computing, Chongqing, China, July 18-20, 1989

1991 Pacific Rim international symposium on FTS, Kawasaki, Japan

1999 Pacific Rim international symposium on Dependable Computing, Hong Kong, China. Keynote: Computer Crime in Hong Kong

(Mr. Anthony Fung) From the HK police department

Computer Crime and Internet Fraud Its evidence for litigation support


Trusted Computing

Trusted Computing Platform Alliance (TCPA) in 1999

TCG since 2003 TPM → TCM (Trusted C Module) 2008 Trusted root → security chip → trusted BIOS →

trusted OS → trusted systems Basically for PCs in the area of secure computing


IEEE Transactions on Dependable and Secure Computing

Since 2004 Separate dependable computing from

secure computing


System dependability The system dependability situation has been getting w

orse rather than improving in recent years. Quoting the AMSD Roadmap, “the availability that was typically achievable by (wired) telecommunication services, and computer systems in the 1990s was 99.999 percent to 99.9 percent. Now cellular phone services, and web-based services, typically achieve an availability of only 99 per cent to 90 per cent” (AMSD Roadmap 2003, p. 31).

The European Commission’s Accompanying Measure on System Dependability


New challenges Three key requirements for computers

High performance Low power Dependability

Nano-ICs, more vulnerable– to transient (or soft) errors to transient (or soft) errors – to permanent malfunctions due to materials aging or to permanent malfunctions due to materials aging or

wearout mechanismswearout mechanisms. . Nano-scale IC reliability Counterfeit ICs Dependability and security in cloud computing Signal integrality Dependant software needs evidence.


Nano-scale IC reliability The "International Technology Roadmap for

Semiconductors" [SIA] estimates that by 2019 the feature size of process technology will reach 7nm, but only between 10% and 20% of chips will be defect free.

Power densities to skyrocket and on-chip temperatures to increase

Small delay defects, adjacent line coupling, crosstalk and process variation induced unreliability variability-tolerant design appropriate measures are taken, such as fault

tolerance, redundancy, repair and reconfiguration.


Counterfeit Electronic Components

These are incidents that jeopardize the performance and reliability of electronics.

Marking indicates an Op Amp from ADI…

… but contains die for a Voltage Reference from PMI

Evidence of prior marking for a part with inferior performance …

… accompanied by bogus test report

Device lead condition shows parts were used

Part number indicates a CLCC package, but this package is a CDP…


Baofeng.com incident in China

Network outages in Jiangsu, Anhui, Guangxi, Henan, Gansu, and Zhejiang in China, May 19, 2009

The network failure was led by the domain name system (DNS) failure of Baofeng.com, the website of the Chinese music player provider

The failure further caused the surge of DNS server visits and the decrease of processing performance of the network.

The servers of DNSPod were attacked by a malicious virus.

The incident was caused by a software fault or an attack?--- Maybe both


Bohrbugs and Mandelbugs Bohrbugs

An unusual software bug that consistently makes its presence known under conditions that are either well-defined, possibly unknown or both.

Mandelbugs A bug whose behavior doesn't appear malicious, b

ut has such a high level of complexity that it appears when errors are accumulated for some time.

Bohrbugs behaving like Mandelbugs Becoming an attack


Dependability in the Cloud

On April 26 2008, Amazon’s Elastic Cloud (EC2) had an outage due to a single customer applying a very large

set of unusual firewall rules triggering a performance degradation bug in

Amazon’s distributed firewall. Availability and privacy are serious challenges for

applications hosted on cloud infrastructure.


Challenges on cloud infrastructure

Cloud applications increase risk levels Sharing of cloud resources by entities that engage in a

wide range of behaviors and employ best practices to varying degrees

An environment with a few large cloud infrastructure providers increases the risk of common mode outages affecting a

large number of applications provides highly visible targets for attackers.

Multiple administrative domains between the application and infrastructure operators reduces end-to-end system visibility and error propagation information, thus making problem detection and diagnosis very difficult.

A cloud provider's economies of scale allow levels of investment in redundancy and dependability, but smaller operators may not.


Old FTC techniques facing new environments

Checkpointing Redundancy Software fault-tolerance in middleware ECC in mass storage systems Fault detection and diagnosis in virtual machines Assessment of dependability and security


Checkpointing for supercomputers

Periodic checkpointing → cooperative checkpointing At runtime, the application requests a checkpoint. The system grants or denies the checkpoint (to ski

p some of them) based on various system-wide heuristics, including

disk or network usage and reliability information. Using cooperative checkpointing in one instance

reduced bounded slowdown by a factor of nine, improved system utilization, and lost no more

work to failures than periodic checkpointing even when event prediction had a 90% false

negative rate.

19INSTITUTE OF COMPUTING TECHNOLOGY CHINESE ACADEMY OF SCIENCESINSTITUTE OF COMPUTING TECHNOLOGY CHINESE ACADEMY OF SCIENCES19

Violation Occurs Violation detected

Processor State

Noise-verifiedNoise-verifiedNoise-speculativeNoise-speculative

• Sliding window based on sensor delay• Delayed-commit: completed results buffered in the buffers until verified to

be correct– Noise-speculative– Noise-verified

• Rollback to a previous noise-verified state when a violation is detected

Noise-speculativeNoise-verified

Committed state

Committed state

Checkpointing at micro-operation level


Redundancy

At the application level and at a hardware level. Byzantine fault tolerance

Algorithms that are robust to arbitrary types of failures in distributed algorithms.

Do not require any centralized control that have some guarantee of always working correctly.

Data integrity Redundancy in different places RAID (redundant array of independent disks), a fault-tolerant

storage device that uses data redundancy. Synchronization is a big challenge.


Software fault-tolerance in middleware

Optimal fault tolerance strategy for both stateless and stateful Web services Retry Recovery block N-version programming

Network characteristics: Freedom Dynamic Multi-tier service

Debug performance problems of multi-tier services of black boxes.


Soft errors Soft errors involve changes to data Cosmic rays creating energetic neutrons and

protons The importance of soft errors increases as chip

technology advances. chip-level soft error

the radioactive atoms in the chip's material decay and release alpha particles into the chip.

Built-in Soft Error Resilience (BISER) Cell system-level soft error

the data being processed is hit with a noise phenomenon


Transient Faults

Program replication N-version programming Time redundant technique, Virtual duplex systems Tandem Nonstop Cyclone is a custom system

designed to use process replicas for transaction processing workloads.

Transient Fault Tolerance for Multi-core Architectures Redundancy at the process level Ensuring correct hardware execution or ensuring

correct software execution


Assessment of dependability and security

The original definition of dependability is the ability to deliver service that can justifiably be trusted. Justification Evaluation Banchmarking Standardization

A dependability and security gap that is often perceived by users as a lack of trustworthiness in computer applications, and that is in fact undermining the network and service infrastructures that constitute the very core of the knowledge-based society.


Difficulties for assessment The assessment of dependability in a standard and

comparable way, considering all Component failures Software bugs Human mistakes Interaction mistakes Malicious attacks

The quality of measurements The assessment of dependability in component

based, dynamic and adaptive systems and networks The integration with the development process


Denial of service (DoS)

Effects of DoS attacks are experienced by users as a severe slowdown, service quality degradation, or service disruption.

We need accurate, quantitative, and versatile DoS impact metrics regardless of the underlying mechanism for service denial, attack dynamics, legitimate traffic mix, or network topology.

Measuring DoS through selected legitimate traffic parameters: packet loss, traffic throughput or goodput, request/response delay, transaction duration, and allocation of resources.


Confident computing

Conceptual games

Trustworthy computing

Trusted computing

Secure computing

Robustness

Reliability

Survivability

Cybersecurity

Safety

Manageability

Assurance

Dependable computing

Availability

Maintainability

Integrity

Controllability

Adoptability

Usability


Concluding remarks

Dependable computing is a forever topic for information technology Dependability is as important as high performance,

and low power. New challenges are coming with the advance of IT The gap between academia and industry Concentrate on practical problems, rather than

conceptual games

backward and forward looking at dependable and secure computing

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