Multi-party computation with omnipresent adversary

Secure multi-party computation (MPC) protocols enable a set of n mutually distrusting participants P 1, ..., P n , each with their own private input x i , to compute a function Y = F(x 1, ..., x n ), such that at the end of the protocol, all participants learn the correct value of Y, while secrecy of the private inputs is maintained. Classical results in the unconditionally secure MPC indicate that in the presence of an active adversary, every function can be computed if and only if the number of corrupted participants, t a , is smaller than n/3. Relaxing the requirement of perfect secrecy and utilizing broadcast channels, one can improve this bound to t a  < n/2. All existing MPC protocols assume that uncorrupted participants are truly honest, i.e., they are not even curious in learning other participant secret inputs. Based on this assumption, some MPC protocols are designed in such a way that after elimination of all misbehaving participants, the remaining ones learn all information in the system. This is not consistent with maintaining privacy of the participant inputs. Furthermore, an improvement of the classical results given by Fitzi, Hirt, and Maurer indicates that in addition to t a actively corrupted participants, the adversary may simultaneously corrupt some participants passively. This is in contrast to the assumption that participants who are not corrupted by an active adversary are truly honest. This paper examines the privacy of MPC protocols, and introduces the notion of an omnipresent adversary, which cannot be eliminated from the protocol. The omnipresent adversary can be either a passive, an active or a mixed one. We assume that up to a minority of participants who are not corrupted by an active adversary can be corrupted passively, with the restriction that at any time, the number of corrupted participants does not exceed a predetermined threshold. We will also show that the existence of a t-resilient protocol for a group of n participants, implies the existence of a t’-private protocol for a group of n′ participants. That is, the elimination of misbehaving participants from a t-resilient protocol leads to the decomposition of the protocol. Our adversary model stipulates that a MPC protocol never operates with a set of truly honest participants (which is a more realistic scenario). Therefore, privacy of all participants who properly follow the protocol will be maintained. We present a novel disqualification protocol to avoid a loss of privacy of participants who properly follow the protocol.

Assessment of costs : challenge to validity of client agreement between party entitled to costs and its solicitors

In ASIC v Atlantic 3 Financial (Aust) Pty Ltd [2006] QCA 540 the Queensland Court of Appeal dismissed an appeal from the decision of Mullins J at first instance in ASIC v Atlantic 3 Financial (Aust) Pty LTd [2006] QSC 152, the majority concluding that the client agreement in issue was not inconsistent with s48 of the Queensland Law Society Act 1952.

Party to litigation insolvent company - costs order against non-party liquidator

In Kimtran Pty Ltd v Downie [2003] QDC 043 the court allowed in part an appeal from the refusal by the Queensland Building Tribunal to order the respondent liquidators pay the appellants' costs of proceedings in the Tribunal. The decision involved an examination of authorities which have considered the circumstances in which it is in the interests of justice to make an order for costs against a non-party.

Should the court direct that costs ordered to be recovered on the indemnity basis be assessed by reference to a costs agreement between the successful party and their solicitors?

The decision in Hook v Boreham & QBE Insurance (Australia) Limited [2006] QDC 304 considered whether the court should go further than order that costs be assessed on the indemnity basis, but should also specify the basis by which those indemnity costs should be determined. The decision makes it clear that under r704(3) of the Uniform Civil Procedure Rules, questions of that nature are ordinarily preserved to the discretion of the Registrar.

Malleability attacks on multi-party key agreement protocols

Multi-party key agreement protocols indirectly assume that each principal equally contributes to the final form of the key. In this paper we consider three malleability attacks on multi-party key agreement protocols. The first attack, called strong key control allows a dishonest principal (or a group of principals) to fix the key to a pre-set value. The second attack is weak key control in which the key is still random, but the set from which the key is drawn is much smaller than expected. The third attack is named selective key control in which a dishonest principal (or a group of dishonest principals) is able to remove a contribution of honest principals to the group key. The paper discusses the above three attacks on several key agreement protocols, including DH (Diffie-Hellman), BD (Burmester-Desmedt) and JV (Just-Vaudenay). We show that dishonest principals in all three protocols can weakly control the key, and the only protocol which does not allow for strong key control is the DH protocol. The BD and JV protocols permit to modify the group key by any pair of neighboring principals. This modification remains undetected by honest principals.

On secure multi-party computation in black-box groups

We study the natural problem of secure n-party computation (in the passive, computationally unbounded attack model) of the n-product function f G (x 1,...,x n ) = x 1 ·x 2 ⋯ x n in an arbitrary finite group (G,·), where the input of party P i is x i  ∈ G for i = 1,...,n. For flexibility, we are interested in protocols for f G which require only black-box access to the group G (i.e. the only computations performed by players in the protocol are a group operation, a group inverse, or sampling a uniformly random group element). Our results are as follows. First, on the negative side, we show that if (G,·) is non-abelian and n ≥ 4, then no ⌈n/2⌉-private protocol for computing f G exists. Second, on the positive side, we initiate an approach for construction of black-box protocols for f G based on k-of-k threshold secret sharing schemes, which are efficiently implementable over any black-box group G. We reduce the problem of constructing such protocols to a combinatorial colouring problem in planar graphs. We then give two constructions for such graph colourings. Our first colouring construction gives a protocol with optimal collusion resistance t < n/2, but has exponential communication complexity O(n*2t+1^2/t) group elements (this construction easily extends to general adversary structures). Our second probabilistic colouring construction gives a protocol with (close to optimal) collusion resistance t < n/μ for a graph-related constant μ ≤ 2.948, and has efficient communication complexity O(n*t^2) group elements. Furthermore, we believe that our results can be improved by further study of the associated combinatorial problems.

Party tricks struggles for votes with a social media audience

With Ten’s new drama Party Tricks set for an October 6 premiere, coverage has focused on the social media campaign to promote the show. In advance of the screening, Ten has created in-character accounts for the lead characters, Kate Ballard (Asher Keddie) and David McLeod (Rodger Corser)...

Wrecking ball: could big tech firms ruin the Spotify party?

YouTube is contemplating the launch of a new music service. But how would such a service fare against established music services like Spotify, Rdio, and Pandora? All these services are referred to as “access-based music services”. They offer music listeners access to millions of songs they can listen to as much as they want for free (with advertising and only basic functionality) or for a monthly subscription fee (without advertising)...

Making the fun stop : youth justice reform in Queensland

In 2013 the newly elected conservative Liberal National Party government instigated amendments to the Youth Justice Act 1992 (Qld). Boot camps replaced court ordered youth justice conferencing. In 2014 there were more drastic changes, including opening the Children’s Court proceedings to the public, permitting publication of identifying information of repeat offenders, removing the principle of ‘detention as a last resort’, facilitating prompt transferral of 17 year olds to adult prisons and instigating new bail offences and mandatory boot camp orders for recidivist motor vehicle offenders in Townsville. This article compares these amendments to the legislative frameworks in other jurisdictions and current social research. It argues that these amendments are out of step with national and international best practice benchmarks for youth justice. Early indications are that Indigenous children are now experiencing increased rates of unsentenced remand. The article argues that the government’s policy initiatives are resulting in negative outcomes and that early and extensive evaluations of these changes are essential.

Engagement party : the heart wants what it does

A 3hr large scale participatory installation/event that included live performance, video works,objects, fabric sculptures and was the result of a three month artist residency undertaken by Cam Lab (Jemima Wyman and Anna Mayer)at the Museum of Contemporary Art Los Angeles California. The exhibition transformed two adjoining spaces in the museum, taking design cues from permanent collection artworks currently on view and encouraged gallery visitors to oscillate between immersion and agency as they occupy the various perspectives proposed by the installation.

Party On! A call for entrepreneurship research that is more interactive, activity based, cognitively hot, compassionate, and prosocial

It is the Journal of Business Venturing's (JBV) 30th birthday. Although the community of entrepreneurship scholars deserves to celebrate JBV's achievements over the last 30 years (and congratulate the journal's parents—Ian Macmillan and S. Venkataraman), my focus is more on the future of entrepreneurship (and by extension JBV). A focus on entrepreneurship is both timeless and timely. On the one hand, entrepreneurship is timeless given the long-recognized importance of entrepreneurs to economies and societies (e.g., Jean Baptiste who supposedly coined the term in about 1800). On the other hand, a discussion of entrepreneurship is timely because now that the field of entrepreneurship has achieved legitimacy, it faces both opportunities and threats. It is thus timely to acknowledge the threats and think about opportunities to advance the field. A discussion of entrepreneurship is also timely because society faces a number of grand challenges (including the durability of poverty, environmental degradation [ Dorado and Ventresca, 2013]), challenges well suited to entrepreneurial responses...

Social media in selected Australian federal and state election campaigns, 2010-15

Campaigning in Australian election campaigns at local, state, and federal levels is fundamentally affected by the fact that voting is compulsory in Australia, with citizens who are found to have failed to cast their vote subject to fines. This means that - contrary to the situation in most other nations – elections are decided not by which candidate or party has managed to encourage the largest number of nominal supporters to make the effort to cast their vote, but by some 10-20% of genuine ‘swinging voters’ who change their party preferences from one election to the next. Political campaigning is thus aimed less at existing party supporters (so-called ‘rusted on’ voters whose continued support for the party is essentially taken for granted) than at this genuinely undecided middle of the electorate. Over the past decades, this has resulted in a comparatively timid, vague campaigning style from both major party blocs (the progressive Australian Labor Party [ALP] and the conservative Coalition of the Liberal and National Parties [L/NP]). Election commitments that run the risk of being seen as too partisan and ideological are avoided as they could scare away swinging voters, and recent elections have been fought as much (or more) on the basis of party leaders’ perceived personas as they have on stated policies, even though Australia uses a parliamentary system in which the Prime Minister and state Premiers are elected by their party room rather than directly by voters. At the same time, this perceived lack of distinctiveness in policies between the major parties has also enabled the emergence of new, smaller parties which (under Australia’s Westminster-derived political system) have no hope of gaining a parliamentary majority but could, in a close election, come to hold the balance of power and thus exert disproportionate influence on a government which relies on their support.

Nuori konservatiivi : Tuure Junnila ja hänen poliittinen toimintansa vuoteen 1956

Tuure Junnila, PhD (1910-1999) was one of Finland's most renowned conservative politicians of the post-war period. Junnila is remembered primarily as a persistent opponent of Urho Kekkonen, a long-term Member of Parliament, a conspicuous opposition member and a prolific political writer. Junnila's ideologies and political views were conservative, and he is one of the most outstanding figures in the history of the National Coalition Party. Junnila also made an extensive career outside of politics, first as an economist and then as an executive of Finland's leading commercial bank Kansallis-Osake-Pankki. The Young Conservative is a partial biography written using traditional historical research methods, which examines Junnila's personal history and his activity in public life up to 1956. The study begins by investigating Junnila's background through his childhood, school years, university studies and early professional career. It also looks at Junnila's work as an economist and practical banker. Particular attention is paid to Junnila's political work, constantly focusing on the following five often overlapping areas: (1) economic policy, (2) domestic policy, (3) foreign and security policy, (4) Junnila and Urho Kekkonen, (5) Junnila, the Coalition Party and Finnish conservatism. In his economic policy, Junnila emphasised the importance of economic stability, opposed socialisation and the growth of public expenditure, defended the free market system and private entrepreneurship, and demanded tax cuts. This policy was very popular within the Coalition Party during the early 1950s, making Junnila the leading conservative economic politician of the time. In terms of domestic policy, Junnila demanded as early as the 1940s that a "third force" should be established in Finland to counterbalance the agrarian and labour parties by uniting conservative and liberal ideologies under the same roof. Foreign and security policy is the area of Junnila's political activity which is most clearly situated after the mid-1950s. However, Junnila's early speeches and writings already show a striving towards the unconditional neutrality modelled by Switzerland and Sweden and a strong emphasis on Finland's right to internal self-determination. Junnila, as did the Coalition Party as a whole, adopted a consistently critical approach towards Urho Kekkonen between 1951 and 1956, but this attitude was not as bluntly negative and all-round antagonistic as many previous studies have implied. Junnila was one of the leading Finnish conservatives of the early 1950s and in all essence his views were analogous to the general alignment of the Coalition Party at the time: conservative in ideology and general policy, and liberal in economic policy.

from "The Roving Party"

They walked down through a dry creek bed lined with swamp gums grown so close together they appeared as one living whole. The men passed around these trees in single file, among sun shafts which pierced the canopy but threw no light upon their faces nor warmed their bones. In the gloom the air was thick with flies and the mushrooms grew like the sightless larvae of some queer and unnamed vermin. Before long they found themselves among a stand of trees which had been stripped of their bark for windbreaks. The naked trunks were carved over with bisected circles, detailings of the moon and sun, images of snakes and roo. The Parramatta men gazed at the finely wrought icons but John Batman found more to hold his attention. Pressed onto the flesh of the tree was a bloody handprint. Batman removed his hat and crouched to examine the ground and Black Bill joined him. One injured man had passed this way...