Scientific articles


FEDERATED LEARNING 

T. Chu, N. Laoutaris, “FedQV: Leveraging Quadratic Voting in Federated Learning,” ACM SIGMETRICS’24. [preprint].

T. Chu, A. Garcia-Recuero, C. Iordanou, G. Smaragdakis, N. Laoutaris, “Securing Federated Sensitive Topic Classification against Poisoning Attacks,” NDSS’23. [pdf]

R. Wang, X. Wang, H. Chen, J. Decouchant, S. Picek, N. Laoutaris, K. Liang, “MUDGUARD: Taming Malicious Majorities in Federated Learning using Privacy-Preserving Byzantine-Robust Clustering,” [arXiv:2208.10161].

T. Chu, M. Yang, N. Laoutaris, A. Markopoulou, “PriPrune: Quantifying and Preserving Privacy in Pruned Federated Learning,” [arXiv:2310.19958].


APPLICATIONS OF BIG DATA AND MACHINE LEARNING 

E. Cabana, A. Lutu, E. Frias-Martinez, N. Laoutaris, “Improving Epidemic Risk Maps Using Mobility Information from Mobile Network Data,” ACM SIGSPATIAL’22. (extended abstract, full version at SpatialEpi’22 workshop).


DATA ECONOMY

D. Isler, S. Hwang, Y. Nakatsuka, N. Laoutaris, G. Tsudik “Puppy: A Publicly Verifiable Watermarking Protocol,” [arXiv:2312.09125].

D. Isler, E. Cabana, A. Garcia-Recuero, G. Koutrika, N. Laoutaris, “FreqyWM: Frequency Watermarking for the New Data Economy,” ICDE’24. [pdf]

S. Andres Azcoitia, C. Iordanou, N. Laoutaris, “Understanding the Price of Data in Commercial Data Marketplaces,” ICDE’23. [arXiv:2111.04427] [slides] [dataset]

P. Maesen, D. İşler, N. Laoutaris, Z. Erkin, “Image Watermarking for Machine Learning Datasets,” ACM Data Economy Workshop, 2023. [pdf]

T. Hristov, D. İşler, N. Laoutaris, Z. Erkin, “Graph Database Watermarking Using Pseudo-Nodes,” ACM Data Economy Workshop, 2023. [pdf]

S. Andres Azcoitia, M. Paraschiv, N. Laoutaris, “Computing the Value of Spatio-Temporal Data in Wholesale and Retail Data Marketplaces,” ACM SIGSPATIAL’22. [arXiv:2002.11193]

S. Andres Azcoitia, N. Laoutaris, “A Survey of Data Marketplaces and Their Business Models,” ACM SIGMOD Record, Vol. 51, No. 3, Sep. 2022. [arXiv:2201.04561]

S. Andres Azcoitia, C. Iordanou, N. Laoutaris, “Measuring the Price of Data in Commercial Data Marketplaces,” ACM Data Economy Workshop, 2022.

M. Pachilakis, P. Papadopoulos, N. Laoutaris, E. Markatos, N. Kourtellis, “YourAdvalue: Measuring Advertising Price Dynamics without Bankrupting User Privacy,” ACM SIGMETRICS’22. [pdf]

N. Laoutaris and C. Iordanou, “What do Information Centric Networks, Trusted Execution Environments, and Digital Watermarking have to do with Privacy, the Data Economy, and their future?,” ACM CCR, Vol. 51, No. 1, Jan. 2021. [pdf]

S. Andres Azcoitia, N. Laoutaris, “Try Before You Buy: A practical data purchasing algorithm for real-world data marketplaces,” ACM Data Economy Workshop, 2022. [arXiv:2012.08874]

N. Laoutaris, “Why Online Services Should Pay You for Your Data? The Arguments for a Human-Centric Data Economy,” IEEE Internet Computing, Vol. 23, No. 5, Dec. 2019. [pdf]

M. Paraschiv, N. Laoutaris, “Valuating User Data in a Human-Centric Data Economy,” [arXiv:1909.01137].


DISINFORMATION / FAKE NEWS 

N. Salamanos, P. Leonidou, N. Laoutaris, M. Sirivianos, M. Aspri, M. Paraschiv, “HyperGraphDis: Leveraging Hypergraphs for Contextual and Social-Based Disinformation Detection,” ICWSM’24 [preprint].

M. Paraschiv, N. Salamanos, C. Iordanou, N. Laoutaris, M. Sirivianos, “A Unified Graph-Based Approach to Disinformation Detection using Contextual and Semantic Relations,” ICWSM’22. [preprint]


PRIVACY / TRANSPARENCY

M. Götze, S. Matic, C. Iordanou, G. Smaragdakis and N. Laoutaris, “Measuring Web Cookies in Governmental Websites,” ACM WebSci’22. [pdf]

S. Matic, C. Iordanou, G. Smaragdakis, N. Laoutaris, “Identifying Sensitive URLs at Web-Scale,” ACM IMC’20. [pdf]

C. Iordanou, N. Kourtellis, J. M. Carrascosa, C. Soriente, R. Cuevas, N. Laoutaris, “Beyond content analysis: Detecting targeted ads via distributed counting,” ACM CoNEXT’19. [pdf] [slides]

N. Laoutaris, “Data Transparency: Concerns and Prospects,” Proceedings of the IEEE, Vol. 106, No. 11, Nov. 2018. [pdf]

C. Iordanou, G. Smaragdakis, I. Poese, N. Laoutaris, “Tracing Cross Border Web Tracking,” ACM IMC’18. [pdf[Distinguished Paper Award]

C. Iordanou, C. Soriente, M. Sirivianos, N. Laoutaris, “Who is Fiddling with Prices? Building and Deploying a Watchdog Service for E-commerce,” ACM SIGCOMM’17. [pdf] [dataset]

P. Papadopoulos, N. Kourtellis, P. Rodriguez, N. Laoutaris, “If you are not paying for it, you are the product: How much do advertisers pay to reach you?,” ACM IMC’17. [pdf]

R. Gonzalez, C. Soriente, N. Laoutaris, “User profiling in the time of HTTPS,” ACM IMC’16. [pdf]

F. Papaodyssefs, C. Iordanou, J. Blackburn, N. Laoutaris, K. Papagiannaki, “Web Identity Translator: Behavioral Advertising and Identity Privacy with WIT,” ACM HotNets’15. [pdf]

J. M. Carrascosa, J. Mikians, R. Cuevas, V. Erramilli, N. Laoutaris, “I Always Feel Like Somebody’s Watching Me. Measuring Online Behavioural Advertising,” ACM CoNEXT’15. [pdf]

J. Mikians, L. Gyarmati, V. Erramilli, N. Laoutaris, “Crowd-assisted Search for Price Discrimination in E-Commerce: First results,” ACM CoNEXT’13. [pdf]

J. Mikians, L. Gyarmati, V. Erramilli, N. Laoutaris, “Detecting price and search discrimination on the Internet,” in Proc. of ACM HotNets’12. [pdf]

T. Lauinger, N. Laoutaris, P. Rodriguez, T. Strufe, E. Biersack, E. Kirda, “Privacy Risks in Named Data Networking: What is the Cost of Performance?,” Editorial note ACM Comp. Comm. Rev., Oct. 2012.  [pdf]


INTELLIGENT TRANSPORTATION

B. Cici, A. Markopoulou and N. Laoutaris, “SORS: A Scalable Online Ridesharing System,” ACM IWCTS’16. [pdf]

S. Meichanetzoglou, S. Ioannidis, N. Laoutaris, “Testing for common sense (violation) in airline pricing or how complexity asymmetry defeated you and the web,” [arXiv:1509.05382].

B. Cici, A. Markopoulou and N. Laoutaris, “Designing an On-Line Ride-Sharing System,” ACM Sigspatial’15. [pdf]

B. Cici, A. Markopoulou, E. Frias-Martinez, N. Laoutaris, “Assessing the potential of ride-sharing using mobile and social data: A tale of 2 continents and 4 cities,” ACM UbiComp’14.[pdf]

B. Cici, A. Markopoulou, E. Frias-Martinez, N. Laoutaris, “Quantifying the Potential of Ride-Sharing using Call Description Records,” in Proc. of ACM HotMobile’13. [pdf]


BULK TRANSFERS ON THE INTERNET

N. Laoutaris, M. Sirivianos, X. Yang, P. Rodriguez, “Inter-Datacenter Bulk Transfers with NetStitcher,” in Proc. of ACM SIGCOMM’11. [pdf]

N. Laoutaris, G. Smaragdakis, P. Rodriguez, R. Sundaram,  “Delay Tolerant Bulk Data Transfers on the Internet,” in Proc. of ACM SIGMETRICS’09. [pdf] [Long version in ACM/IEEE Transactions on Networking].

N. Laoutaris, P. Rodriguez, “Good Things Come to Those Who (Can) Wait or How to Handle Delay Tolerant Traffic and Make Peace on the Internet,” in Proc. of ACM HotNets’08. [pdf]


SOCIAL NETWORKS

S. Traverso, K. Huguenin, I. Trestian, V. Erramilli, N. Laoutaris and K. Papagiannaki, “TailGate: Handling long-tail content with a little help from friends” in Proc. of WWW’12. [pdf] [Long version in IEEE Transactions on Parallel and Distributed Systems].

J.-M. Pujol, V. Erramilli, G. Siganos, X. Yang, N. Laoutaris, P. Chhabra, P. Rodriguez,  “The Little Engine(s) that could: Scaling Online Social Networks,” in Proc. of ACM SIGCOMM’10.  [pdf] [Long version in ACM/IEEE Transactions on Networking].


ENERGY EFFICIENCY

E. Goma, M. Canini, A. Lopez, N. Laoutaris, D. Kostic, P. Rodriguez, R. Stanojevic, “Insomnia in the Access or How to Curb Access Network Related Energy Consumption,” in Proc. of ACM SIGCOMM’11. [pdf]

V. Valancius, N. Laoutaris, L. Massoulie, C. Diot, P. Rodriguez, “Greening the Internet with Nano Data Centers,” in Proc. of ACM CoNEXT’09. [pdf]

N. Laoutaris, P. Rodriguez, L. Massoulie, “ECHOS: edge capacity hosting overlays of nano data centers,” ACM Comp. Comm. Rev., vol. 38, no. 1, pp.51-54,  Jan. 2008. [pdf]


NETWORK ECONOMICS

A. Lodhi, A.Dhamdhere, N. Laoutaris, C. Dovrolis, “Complexities in Internet Peering: Understanding the “Black” in the “Black Art,” IEEE INFOCOM’15. [pdf]

J. Cardona, R. Stanojevic, N. Laoutaris, “Collaborative consumption for mobile broadband: a quantitative study,” ACM CoNEXT’14. [pdf]

L. Gyarmati, N. Laoutaris, K. Sdrolias, P. Rodriguez, C. Courcoubetis, “From advertising profits to bandwidth prices – A quantitative methodology for negotiating premium peering,”NetEcon’14. [Long version in ACM Transactions on Internet Technology]. [pdf]

L. Gyarmati, R. Stanojevic, M. Sirivianos, N. Laoutaris, “Sharing the Cost of Backbone Networks: Cui Bono?,” in Proc. of ACM IMC’12. [pdf]

L. Gyarmati, M. Sirivianos, N. Laoutaris, “Sharing the Cost of Backbone Networks: Simplicity vs. Precision,” in Proc. of NetEcon’12.

J. Otto, R. Stanojevic, N. Laoutaris, “Temporal Rate Limiting: cloud elasticity at a flat fee,” in Proc. of NetEcon’12. [pdf]

R. Stanojevic, N. Laoutaris, P. Rodriguez, “On Economic Heavy Hitters: Shapley value analysis of 95th-percentile pricing,” in Proc. of ACM IMC’10. [pdf]

J. Londoño, A. Bestavros, N. Laoutaris, “Trade & Cap: A Customer-Managed, Market-Based System for Trading Bandwidth Allowances at a Shared Link,” in Proc. of NetEcon’10. [Long version in Computer Networks journal].

P. Chhabra, N. Laoutaris, P. Rodriguez, and R. Sundaram, “Home is where the (Fast) Internet is: Flat-rate Compatible Incentives for Reducing Peak Load,” ACM HomeNets’10.


WIRELESS/MOBILE

C. Rossi, N. Vallina-Rodriguez, V. Erramilli, Y. Grunenberger, L. Gyarmati, N. Laoutaris, R. Stanojevic, K. Papagiannaki, P. Rodriguez, “3GOL: Power-boosting ADSL using 3G OnLoading,” ACM CoNEXT’13. [pdf]

N. Vallina, L. Gyarmati, Y. Grunenberger , R. Stanojevic, V. Erramilli, N. Laoutaris, K. Papagiannaki, “When David can help Goliath: the case for cellular augmentation of wired networks,” in Proc. of ACM HotNets’12. [pdf]


BITTORRENT

R. Cuevas, N. Laoutaris, X. Yang, G. Siganos, P. Rodriguez, “Deep Diving into BitTorrent Locality,” in Proc. of IEEE INFOCOM’11. [pdf] [Long version in IEEE Transactions on Parallel and Distributed Systems].

N. Laoutaris, D. Carra, P. Michardi, “Uplink Allocation Beyond Choke/Unchoke or How to Divide and Conquer Best,” in Proc. of ACM CoNEXT’08. [pdf]


OVERLAY CONSTUCTION

N. Laoutaris, L. Poplawski, R. Rajaraman, R. Sundaram, and S.-H. Teng, “Bounded Budget Connection (BBC) games or How to make friends and influence people, on a budget,” in Proc. of  ACM PODC’08. [pdf]  [Long version in  J. Comput. Syst. Sci.].

G. Smaragdakis, V. Lekakis, N. Laoutaris, A. Bestavros, J. Byers, M. Roussopoulos, “The EGOIST Overlay Routing System,” in Proc. of ACM CoNEXT’08. [pdf] [Long version in ACM/IEEE Transactions on Networking].

G. Smaragdakis, N. Laoutaris, P. Michiardi, A. Bestavros, J. Byers, M. Roussopoulos, “Swarming on optimized graphs for n-way broadcast,” in Proc. of IEEE INFOCOM’08. [Long version in IEEE Transactions on Parallel and Distributed Systems].

N. Laoutaris, G. Smaragdakis, A. Bestavros, and J. Byers, “Implications of selfish neighbor selection in overlay networks,” in Proc. of IEEE INFOCOM ’07, Anchorage, AK, May 2007. 


REPLICATION

N. Laoutaris, G. Smaragdakis, K. Oikonomou, I. Stavrakakis, and A. Bestavros, “Distributed placement of service facilities in large-scale networks,” in Proc. of IEEE INFOCOM ’07, Anchorage, AK, May 2007. [Long version in ACM/IEEE Transactions on Networking].

N. Laoutaris, O. Telelis, V. Zissimopoulos, and I. Stavrakakis, “Distributed selfish replication,” IEEE Transactions on Parallel and Distributed Systems, vol. 17, no. 12, pp. 1401–1413, Dec. 2006.

N. Laoutaris, V. Zissimopoulos, and I. Stavrakakis, “On the optimization of storage capacity allocation for content distribution,” Computer Networks, vol. 47, no. 3, pp. 409–428, Feb. 2005.

N. Laoutaris, V. Zissimopoulos, and I. Stavrakakis, “Joint object placement and node dimensioning for internet content distribution,” Information Processing Letters, vol. 89, no. 6, pp. 273–279, Mar. 2004.

N. Laoutaris, O. Telelis, V. Zissimopoulos, and I. Stavrakakis, “Local utility aware content replication,” in Proc. of IFIP Networking ’05.

N. Laoutaris, V. Zissimopoulos, and I. Stavrakakis, “Storage capacity allocation algorithms for hierarchical content distribution,” in Proc. of IFIP Net-Con ’04.

N. Laoutaris, A. Panagakis, and I. Stavrakakis, “Content distribution through autonomic content and storage management,” in Proc. WAC ’04.


CACHING

N. Laoutaris, G. Zervas, A. Bestavros, and G. Kollios, “The cache inference problem and its application to content and request routing,” in Proc. of IEEE INFOCOM ’07.

N. Laoutaris, G. Smaragdakis, A. Bestavros, and I. Stavrakakis, “Mistreatment in distributed caching groups: Causes and implications,” in Proc. of IEEE INFOCOM ’06.

N. Laoutaris, G. Smaragdakis, A. Bestavros, I. Matta, and I. Stavrakakis, “Distributed selfish caching,” IEEE Transactions on Parallel and Distributed Systems, vol. 18, no. 10, Oct. 2007.

N. Laoutaris, “A closed-form method for LRU replacement under generalized power-law demand,” 2007, arXiv:0705.1970v1

G. Smaragdakis, N. Laoutaris, A. Bestavros, I. Matta, and I. Stavrakakis, “Mistreatment-resilient distributed caching,” Computer Networks, vol. 51, no. 11, pp. 2917–2937 , 2007.

G. Smaragdakis, N. Laoutaris, I. Matta, A. Bestavros, and I. Stavrakakis, “A feedback control approach to mitigating mistreatment in distributed caching groups,” in Proc. of IFIP Networking ’06.

N. Laoutaris, H. Che, and I. Stavrakakis, “The LCD interconnection of LRU caches and its analysis,” Performance Evaluation, vol. 63, no. 7, pp. 609–634, July 2006. [PS]

E. Balafoutis, A. Panagakis, N. Laoutaris, and I. Stavrakakis, “Study of the impact of replacement granularity and associated strategies on video caching,” Cluster Computing, vol. 8, no. 1, pp. 89–100, Jan. 2005.

N. Laoutaris, S. Syntila, and I. Stavrakakis, “Meta algorithms for hierarchical web caches,” in Proc. IEEE IPCCC ’04, Phoenix, Arizona, Apr. 2004. [pdf]

E. Balafoutis, A. Panagakis, N. Laoutaris, and I. Stavrakakis, “The impact of replacement granularity on video caching,” in Proc. IFIP Networking ’02.


MULTIMEDIA STREAMING

C. C. Vassilakis, N. Laoutaris, and I. Stavrakakis, “On the Impact of Playout Scheduling on the Performance of Peer-to-Peer Live Streaming,” Computer Networks, Vol. 53, No. 4, pp. 456-469, 2009.

C. C. Vassilakis, N. Laoutaris, and I. Stavrakakis, “The impact of playout policy on the performance of P2P live streaming,” in Proc. of ACM MMCN ’08, San Jose, California, Jan 2008.

N. Laoutaris, B. V. Houdt, and I. Stavrakakis, “Optimization of a packet video receiver under different levels of delay jitter: An analytical approach,” Performance Evaluation, vol. 55, no. 3-4, pp. 251–275, Feb. 2004. [PS]

N. Laoutaris and I. Stavrakakis, “An analytical design of optimal playout schedulers for packet video receivers,” Computer Communications, vol. 26, no. 4, pp. 294–303, Mar. 2003.

N. Laoutaris and I. Stavrakakis, “Intrastream synchronization for continuous media streams: A survey of playout schedulers,” IEEE Network Magazine, vol. 16, no. 3, May 2002.

N. Laoutaris, G. Boukeas, and I. Stavrakakis, “Design of optimal playout schedulers for packet video receivers,” in Proc. QofIS ’01, Coimbra, Portugal, Sept. 2001.

N. Laoutaris and I. Stavrakakis, “Adaptive playout strategies for packet video receivers with finite buffer capacity,” in Proc. IEEE ICC ’01, Helsinki, Finland, June 2001.

N. Karelos, N. Laoutaris, P. Balaouras, and I. Stavrakakis, “Endsystem performance issues for continuous media streaming applications,” in Proc. ATM & IP, Ilkley, West Yorkshire, U.K, July 2000.


OTHER

C. Xenakis, N. Laoutaris, L. Merakos, and I. Stavrakakis, “A generic characterization of the overheads imposed by IPsec and associated cryptographic algorithms,” Computer Networks, vol. 50, no. 17, pp. 3225–3241, Dec.
2006.

N. Kranitis, A. Merentitis, N. Laoutaris, G. Theodorou, A. Paschalis, D. Gizopoulos, and C. Halatsis, “Optimal periodic testing of intermittent faults in embedded pipelined processor applications,” in Proc. of DATE ’06, Munich, Germany, Mar. 2006.