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Distributed Systems. Latest relevant Techniques and applications. Outline. Services: DNSSEC Architecture Models: Grid Network Protocols: IPv6 Design Issues: Security The Future: World Community Grid. Services: DNSSEC. DNS.
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Distributed Systems Latest relevant Techniques and applications
Outline • Services: DNSSEC • Architecture Models: Grid • Network Protocols: IPv6 • Design Issues: Security • The Future: World Community Grid
DNS • Large distributed database for name-to-ip resolution (ex: DNS Query) • Was not originally designed with security in mind – naturally has security flaws: • Packet interception • DNS cache poisoning / Name chaining • ID guessing [RFC 3833, 2004]
DNSSEC – suite of IETF specifications for securing information provided by DNS and IP. • Authentication of origin • Data integrity • Backwards compatibility [RFC 3833, 2004]
RFC 2065 published in 1997, but problems have existed since then and are still being worked out • Did not scale well for the internet • Backwards compatibility • Who should own TLD root keys • Complexity of deployment • Proposed Standard is currently RFC 4033
Works by digitally signing DNS responses to lookups using public-key cryptography. • DNS records RRSIG, DNSKEY, DS, and NSEC DNS records created. • RRSIG is the digital signature of the response. Verified using the public key found in DNSKEY record. • DS records are for designated signers.
Start with a trusted DNS root. Look up the DS record for TLD to verify the DNSKEY records for that TLD. • Next, check if DS record for site.com exists in the TLD zone, and if so, use that to verify the DNSKEY found in the site.com zone. • Finally, verify RRSIG record found in the A records for www.site.com [RFC 4033, 2005]
Grid Architecture • Use idle machine for more efficient use of the resources such as cpu, memory, storage, bandwidth, databases, etc. • Geographically dispersed • Must be provisioned to determine location, availability, and scheduling of resources. [IT Pro, 2004]
Related Terms: Comparison • Utility Computing: Leased like a utility from a company. Expect providers to switch to using grids (Sun, for example) • Cluster computing: machines usually closely coupled and connected through high speed network – generally in the same room. • P2p: considered to be an application that uses grid services for file sharing, whereas the grid can allow for sharing of any resource type.
Cloud computing: Very similar to grid. So similar it’s difficult to pull out the differences and different people state different things… • Overall, many sources mention “on-demand” for cloud computing, whereas grid computing focuses on one problem at a time. [IT Pro, 2004]
Not all applications are efficient on a grid – must have high levels of parallelism in order to be effective and overcome the overhead involved with grid computing.
Defined in 1998 by Internet Engineering Task Force (IETF), RFC 2460 • Main feature is much larger number of addresses • IPv4 uses 32 bits, allowing for 232 addresses, whereas IPv6 uses 128 bits (2128 addresses) • Other changes include network security, improved routing, extensibility, among others. [Geer, 2005]
Many benefits available from the extensive amount of IP addresses. Ex: • Distributed applications on cell phones • Japanese windshield wipers for taxi cabs • Track devices for warranties, upgrade / repair, emergencies • Smart homes [Geer, 2005]
Main difficulty is making the switch from IPv4 to IPv6. • Difficult to mix the two • Users generally do not feel the push to switch, especially since NAT has become widespread
Secure communications between two machines: • Grid Security Infrastructure (GSI) • Mutual authentication • Public key cryptography • Certificates • Single sign-on [Globus]
In grid computing, we can protect the host by: • Sandboxing • Virtualization • Flexible kernel [Chakrabarti et. al., 2008] • Can we protect the privacy of the grid user?
World Community Grid • An idea where the grid exists across the internet, and the world is all connected to the grid • Would allow millions of idle processors to be used more efficiently
Will be very difficult to achieve • Security (unknown users connecting to unknown machines) • Network issues • Control
References • RFC 3833: Threat Analysis of the Domain Name System, The Internet Society, August 2004 • RFC 4033: DNS Security Introduction and Requirements, The Internet Society, March 2005 • http://www.globus.org/security/overview.html • http://www.fh-wedel.de • "Grid computing 101: what's all the fuss about?," IT Professional , vol.6, no.2, pp. 25-33, March-April 2004 • D. Geer, “In Brief: IPv6 and Distributed Applications,” IEEE Distributed Systems Online, vol. 6, no.12, December 2005 • Chakrabarti, A.; Damodaran, A.; Sengupta, S., “Grid Computing Security: A Taxonomy,” Security & Privacy, IEEE, vol. 6, no.1, pp.44-51, Jan-Feb. 2008