What we do and why

The Electronic Colloquium on Computational Complexity (ECCC) was established in 1994 as a forum and repository for the rapid and widespread interchange of ideas, techniques, and research in computational complexity. Posting on the ECCC has the status of a technical report. The Electronic Colloquium on Computational Complexity welcomes papers, short notes, and surveys, with

• relevance to the theory of computation,
• clear mathematical profile, and
• strictly mathematical format.

Central topics

• models of computation and their complexity.
• complexity bounds and trade-offs (with the emphasis on lower bounds).
• complexity theoretic aspects of specific areas including coding theory, combinatorics, cryptography, game theory, logic, machine learning, optimization, property testing, and quantum computation.

For more details see the Call for Papers.

More reading

Here are some papers on the idea and concept of electronic colloquia and ECCC.

• Christoph Meinel, Volker Klotz
  "The first 10 years of the ECCC digital library"
  Communications of the ACM - CACM, vol. 49, no. 1, pp. 131-134, 2006.
• Jochen Bern, Carsten Damm, Christoph Meinel
  "The Electronic Colloquium on Computational Complexity (ECCC): A Digital Library in Use"
  European Conference on Digital Libraries - ECDL, pp. 405-421, 1997.

In the last few days, a Denial of Service attack was launched on universities in Israel, leading the administrators of the Israel Academic network to block access to it from the global internet. Consequently, websites such as ECCC have been accessible only from within the Israeli and European academic networks.

It seems that this blocking was just removed, and we hope it will not be put back in the future.

Needless to say, deciding on such blocking is not in our control, but we do apologize for this disruption of service.

The ECCC has just relocated at the Weizmann Institute of Science. The previous locations were first at the University of Trier (1994-2004), and then at the Hasso Plattner Institute (2004-2016).

Our new URL is eccc.weizmann.ac.il, and the previous URL (eccc.hpi-web.de) is supposed to redirect to the new location. All hyperlinks to reports are still functional after the transition.

Our first priority at the next couple of weeks is to verify that the transition has been performed smoothly and that all existing features work as they used to. (Later on and as circumstances permit, we shall perform various minor improvements, which were on our TODO list for a while.)

Please inform Amir Gonen (amir.gonen@weizmann.ac.il), while CCing Oded Goldreich (oded.goldreich@weizmann.ac.il), as soon as you discover anything that does not function as it used to.

At this point, I would like to thank Christoph Meinel, who has been one of the founders of ECCC and served as its chief editor and head of its local office for 23 years. Special thanks also to Christian Willems, who has provided the technical support for the operation of ECCC for the last few years and has supervised the current transition from the sending side. (I am aware that others deserves much credits as well, but regret that I cannot provide the relevant details at this time. Providing a full account of the history of the establishing of ECCC and its operation since 1994, in the form of a "History of ECCC" page, is on our TODO list.)

Lastly, many thanks to Amir Gonen for performing the transition on the receiving side and for agreeing to undertake the operation from this point on.

Oded Goldreich

After 23 years of running the ECCC, first at the University of Trier, then at the Hasso Plattner Institute, the ECCC will find a new home at the Weizmann Institute.

This smooth transition will happen with the beginning of 2017. We will keep you informed upfront.

In this paper we study syntactic branching programs of bounded repetition
representing CNFs of bounded treewidth.
For this purpose we introduce two new structural graph
parameters $d$-pathwidth and clique preserving $d$-pathwidth denoted
by $pw_d(G)$ and $cpw_d(G)$ where $G$ is a graph.
We show that $cpw_2(G) \leq O(tw(G) \Delta(G))$ ... more >>>

We survey recent and classical results and techniques concerning binary codes in the large distance (or, high-noise) regime, and the closely related notion of $\varepsilon$-balanced codes. Our (hopefully small-biased) column will mainly discuss encoding, and decoding from adversarial errors.

A previous version of this text originally appeared as an ACM ... more >>>

We study uniquely decodable codes and list decodable codes in the high-noise regime, specifically codes that are uniquely decodable from $\frac{1-\varepsilon}{2}$ fraction of errors and list decodable from $1-\varepsilon$ fraction of errors. We present several improved explicit constructions that achieve near-optimal rates, as well as efficient or even linear-time decoding ... more >>>