taken from http://www.coclouds.com/wp-content/uploads/2011/05/variety-clouds-panoramic2-2011-05-21.jpg
Research

An increasing number of businesses and individuals are adopting cloud computing as their main computing infrastructure. In fact, remote data storage (e.g., Amazon S3) and outsourcing of computation (e.g., Google docs) have become a major everyday phenomenon.

Although cloud computing provides great services to costumers, it does trigger many security concerns: Users' data is now stored at untrusted, geographically dispersed, servers and possibly untrusted applications might execute on it. Therefore users lose control of their data and programs, which could be modified or accessed by unauthorized entities. For example, sensitive information could be leaked or tampered with due to malicious or buggy cloud software, leading to undesirable situations.

My research aims at alleviating these concerns of the community, by providing integrity and privacy guarantees for cloud services, in an efficient way. Specifically it offers several types of cryptographic assurances, so that remote data and computations cannot be altered (without being detected) and data managed by cloud applications cannot leak.

Apart from research on cloud computing security, I enjoy working on cryptography, data structures and algorithm design. In the past, I spent some time working on graph algorithms and graph drawing.

Publications
    conferences
  1. Yupeng Zhang, Daniel Genkin, Jonathan Katz, Dimitrios Papadopoulos, and Charalampos Papamanthou. vSQL: Verifying General SQL Queries over Dynamic Outsourced Databases. In Proc. Int. Symposium on Security and Privacy (SSP), San Jose CA, USA, 2017.
  2. Ioannis Demertzis and Charalampos Papamanthou. Fast Searchable Encryption with Tunable Locality. In Proc. ACM Special Interest Group on Management of Data (SIGMOD), Chicago IL, USA, 2017.
  3. Yupeng Zhang, Jonathan Katz, and Charalampos Papamanthou. An Expressive (Zero-Knowledge) Set Accumulator. In Proc. European Symposium on Security and Privacy (EUROSSP), Paris, France, 2017.
  4. Giuseppe Ateniese, Michael T. Goodrich, Vasilis Lekakis, Charalampos Papamanthou, Evripidis Paraskevas, and Roberto Tamassia. Accountable Storage. In Proc. Applied Cryptography and Network Security (ACNS), Kanazawa, Japan, 2017.
  5. Yupeng Zhang, Jonathan Katz, and Charalampos Papamanthou. All Your Queries Are Belong to Us: The Power of File-Injection Attacks on Searchable Encryption. In Proc. USENIX SECURITY Symposium (USENIX SECURITY), Austin TX, USA, 2016.
  6. Sanjam Garg, Payman Mohassel, and Charalampos Papamanthou. TWORAM: Efficient oblivious RAM in Two Rounds with Applications to Searchable Encryption. In Proc. Int. Cryptology Conference (CRYPTO), Santa Barbara CA, USA, 2016.
  7. Ahmed Kosba, Andrew Miller, Elaine Shi, Zikai Wen and Charalampos Papamanthou. Hawk: The Blockchain Model of Cryptography and Privacy-Preserving Smart Contracts. In Proc. Int. Symposium on Security and Privacy (SSP), San Jose CA, USA, 2016.
  8. Dana Dachman-Soded, Chang Liu, Charalampos Papamanthou, Elaine Shi and Uzi Vishkin. Oblivious Network RAM and Leveraging Parallelism to Achieve Obliviousness. In Proc. Int. Conference on the Theory and Application of Cryptology and Information Security (ASIACRYPT), Auckland, New Zealand, 2015.
  9. Yupeng Zhang, Jonathan Katz and Charalampos Papamanthou. IntegriDB: Verifiable SQL for Outsourced Databases. In Proc. Int. ACM Conference on Computer and Communications Security (CCS), Denver CO, USA, 2015.
  10. Hubert Chan, Charalampos Papamanthou, and Zhichao Zhao. On the Complexity of the Minimum Independent Set Partition Problem. In Proc. Int. Computing and Combinatorics Conference (COCOON), Beijing, China, 2015.
  11. Yi Qian, Yupeng Zhang, Xi Chen and Charalampos Papamanthou. Streaming Authenticated Data Structures: Abstraction and Implementation. In Proc. Int. ACM Cloud Computing Security Workshop (CCSW), Scottsdale AZ, 2014.
  12. Yupeng Zhang, Charalampos Papamanthou and Jonathan Katz. ALITHEIA: Towards Practical Verifiable Graph Processing. In Proc. Int. ACM Conference on Computer and Communications Security (CCS), Scottsdale AZ, 2014.
  13. Ahmed E. Kosba, Dimitrios Papadopoulos, Charalampos Papamanthou, Mahmoud F. Sayed, Elaine Shi and Nikos Triandopoulos. TRUESET: Faster Verifiable Set Computations. In Proc. USENIX SECURITY Symposium (USENIX SECURITY), San Diego CA, USA, 2014.
  14. Emil Stefanov, Charalampos Papamanthou and Elaine Shi. Practical Dynamic Searchable Encryption with Small Leakage. In Proc. Int. Network and Distributed System Security Symposium (NDSS), San Diego CA, USA, 2014.
  15. Elaine Shi, Emil Stefanov and Charalampos Papamanthou. Practical Dynamic Proofs of Retrievability. In Proc. Int. ACM Conference on Computer and Communications Security (CCS), Berlin, Germany, 2013.
  16. Charalampos Papamanthou, Elaine Shi, Roberto Tamassia and Ke Yi. Streaming Authenticated Data Structures. In Proc. Int. Conference on the Theory and Applications of Cryptographic Techniques (EUROCRYPT), Athens, Greece, 2013.
  17. Seny Kamara and Charalampos Papamanthou. Parallel and Dynamic Searchable Symmetric Encryption. In Proc. Int. Financial Cryptography and Data Security Conference (FC), Okinawa, Japan, 2013.
  18. Charalampos Papamanthou, Elaine Shi and Roberto Tamassia. Signatures of Correct Computation. In Proc. Int. Theory of Cryptography Conference (TCC), Tokyo, Japan, 2013.
  19. Prateek Mittal, Charalampos Papamanthou and Dawn Song. Preserving Link Privacy in Social Network Based Systems. In Proc. Int. Network and Distributed System Security Symposium (NDSS), San Diego CA, USA, 2013.
  20. Seny Kamara, Charalampos Papamanthou and Tom Roeder. Dynamic Searchable Symmetric Encryption. In Proc. Int. ACM Conference on Computer and Communications Security (CCS), Raleigh NC, USA, 2012.
  21. Charalampos Papamanthou, Roberto Tamassia, and Nikos Triandopoulos. Optimal Verification of Operations on Dynamic Sets. In Proc. Int. Cryptology Conference (CRYPTO), Santa Barbara CA, USA, 2011.
  22. Petros Maniatis, Michael Dietz, and Charalampos Papamanthou. MOMMIE Knows Best: Systematic Optimizations for Verifiable Distributed Algorithms. In Proc. Int. Workshop on Hot Topics in Operating Systems (HotOS), Napa CA, USA, 2011.
  23. Charalampos Papamanthou, Roberto Tamassia, and Nikos Triandopoulos. Optimal Authenticated Data Structures with Multilinear Forms. In Proc. Int. Conference on Pairing-Based Cryptography (PAIRING), Ishikawa, Japan, 2010.
  24. C. Christopher Erway, Alptekin Küpçü, Charalampos Papamanthou, and Roberto Tamassia. Dynamic Provable Data Possession. In Proc. Int. ACM Conference on Computer and Communications Security (CCS), Chicago IL, USA, 2009.
  25. Charalampos Papamanthou, Roberto Tamassia, and Nikos Triandopoulos. Authenticated Hash Tables. In Proc. Int. ACM Conference on Computer and Communications Security (CCS), Alexandria VA, USA, 2008.
  26. Alexander Heitzmann, Bernardo Palazzi, Charalampos Papamanthou, and Roberto Tamassia. Efficient Integrity Checking of Untrusted Network Storage. In Proc. Int. ACM CCS Workshop on Storage Security and Survivability (STORAGESS), Alexandria VA, USA, 2008.
  27. Alexander Heitzmann, Bernardo Palazzi, Charalampos Papamanthou, and Roberto Tamassia. Effective Visualization of File System Access-Control. In Proc. Int. Workshop on Security Visualization (VIZSEC), Boston MA, USA, 2008.
  28. Michael T. Goodrich, Charalampos Papamanthou, Roberto Tamassia, and Nikos Triandopoulos. Athos: Efficient Authentication of Outsourced File Systems. In Proc. Int. Information Security Conference (ISC), Taipei, Taiwan, 2008.
  29. Charalampos Papamanthou, Franco P. Preparata, and Roberto Tamassia. Algorithms for Location Estimation Based on RSSI Sampling. In Proc. Int. ICALP Workshop on Algorithms for Sensor Networks (ALGOSENSORS), Reykjavik, Iceland, 2008.
  30. Roberto Tamassia, Bernardo Palazzi, and Charalampos Papamanthou. Graph Drawing for Security Visualization. In Proc. Int. Conference on Graph Drawing (GD), Heraklion, Greece, 2008.
  31. Charalampos Papamanthou and Roberto Tamassia. Time and Space Efficient Algorithms for Two-Party Authenticated Data Structures. In Proc. Int. Conference on Information and Communications Security (ICICS) Zhengzhou, China, 2007.
  32. Michael T. Goodrich, Charalampos Papamanthou, and Roberto Tamassia. On The Cost of Persistence and Authentication in Skip Lists. In Proc. Int. Workshop on Experimental Algorithms (WEA), Rome, Italy, 2007.
  33. Charalampos Papamanthou and Ioannis G. Tollis. Parameterized st-Orientations of Graphs: Algorithms and Experiments. In Proc. Int. Conference on Graph Drawing (GD), Karlsrühe, Germany, 2006.
  34. Charalampos Papamanthou and Ioannis G. Tollis. Applications of Parameterized st-Orientations in Graph Drawing Algorithms. In Proc. Int. Conference on Graph Drawing (GD)Limerick, Ireland, 2005.
  35. Charalampos Papamanthou, Ioannis G. Tollis, and Martin Doerr. 3D Visualization of Semantic Metadata Models and Ontologies. In Proc. Int. Conference on Graph Drawing (GD), New York City NY, USA, 2004.
  36. Charalampos Papamanthou and Konstantinos Paparrizos. A Visualization of the Primal Simplex Algorithm for the Assignment Problem. In Proc. Int. ACM Conference on Innovation and Technology in Computer Science Education (ITICSE), Thessaloniki, Greece, 2003.
  37. journals
  38. Charalampos Papamanthou, Roberto Tamassia, and Nikos Triandopoulos. Authenticated Hash Tables Based on Cryptographic Accumulators. Algorithmica, 74(2):664-712, 2016.
  39. Dimitrios Papadopoulos, Charalampos Papamanthou, Roberto Tamassia and Nikos Triandopoulos. Practical Authenticated Pattern Matching with Optimal Proof Size. Proceedings of the VLDB Endowment, 8(7):750-761, 2015.
  40. Chris C. Erway, Alptekin Küpçü, Charalampos Papamanthou, and Roberto Tamassia. Dynamic Provable Data Possession. ACM Transactions on Information and System Security, 17(4):15:1-15:29, 2015.
  41. Michael T. Goodrich, Duy Nguyen, Olga Ohrimenko, Charalampos Papamanthou, Roberto Tamassia, Nikos Triandopoulos, and Cristina Videira Lopes. Efficient Verification of Web-Content Searching Through Authenticated Web Crawlers. Proceedings of the VLDB Endowment, 5(10):920-931, 2012.
  42. Charalampos Papamanthou, Konstantinos Paparrizos, Nikolaos Samaras, and Angelo Sifaleras. On the Initialization Methods of an Exterior Point Algorithm for the Assignment Problem. International Journal of Computer Mathematics, 87(8):1831-1846, 2010.
  43. Charalampos Papamanthou and Ioannis G. Tollis. Applications of Parameterized st-Orientations. Journal of Graph Algorithms and Applications, 14(2):337-365, 2010.
  44. Claire Mathieu and Charalampos Papamanthou. Distortion Lower Bounds for Line Embeddings. Information Processing Letters, 108(4):175-178, 2008.
  45. Charalampos Papamanthou and Ioannis G. Tollis. Algorithms for Computing a Parameterized st-Orientation. Theoretical Computer Science, 408:224-240, 2008.
  46. Charalampos Papamanthou, Konstantinos Paparrizos, Nikolaos Samaras, and Konstantinos Stergiou. Worst Case Examples of an Exterior Point Algorithm for the Assignment Problem. Discrete Optimization, 5(3):605-614, 2008.
  47. Charalampos Papamanthou, Konstantinos Paparrizos, and Nikolaos Samaras. A Parametric Visualization Software for the Assignment Problem. Yugoslav Journal of Operations Research, 15(1):147-158, 2005.
  48. Charalampos Papamanthou, Konstantinos Paparrizos, and Nikolaos Samaras. Computational Experience with Exterior Point Algorithms for the Transportation Problem. Journal of Applied Mathematics and Computation, 158:459-475, 2004.
  49. other
  50. Charalampos Papamanthou. Cryptography for Efficiency: New Directions in Authenticated Data Structures. PhD thesis, Brown University, Providence RI, USA, May 2011.
  51. Charalampos Papamanthou. Computing Longest Path Parameterized st-Orientations of Graphs: Algorithms and Applications. Master's thesis, University of Crete, Heraklion, Greece, July 2005.
  52. Charalampos Papamanthou. Effective Programming, Computational Study and Internet Visualization of Network Programming Problems Algorithms. Bachelor's thesis, University of Macedonia, Thessaloniki, Greece, September 2003.