Abstract. Face recognition is increasingly deployed as a means to unobtrusively verify the identity of people. The widespread use of biometrics raises important privacy concerns, in particular if the biometric matching process is performed at a central or untrusted server, and calls for the implementation of Privacy-Enhancing Technologies. In this paper we propose for the first time a strongly privacy-enhanced face recognition system, which allows to efficiently hide both the biometrics and the result from the server that performs the matching operation, by using techniques from secure multiparty computation. We consider a scenario where one party provides a face image, while another party has access to a database of facial templates. Our protocol allows to jointly run the standard Eigenfaces recognition algorithm in such a way that the first party cannot learn from the execution of the protocol more than basic parameters of the database, while the second party does not learn the input image or the result of the recognition process. At the core of our protocol lies an efficient protocol for securely comparing two Paillerencrypted numbers. We show through extensive experiments that the system can be run efficiently on conventional hardware.

Abstract. We show that if a set of players hold shares of a value a ∈ Fp for some prime p (where the set of shares is written [a]p), it is possible to compute, in constant rounds and with unconditional security, sharings of the bits of a, i.e., compute sharingsOur protocol is secure against active adversaries and works for any linear secret sharing scheme with a multiplication protocol. The complexity of our protocol is O( log ) invocations of the multiplication protocol for the underlying secret sharing scheme, carried out in O(1) rounds.This result immediately implies solutions to other long-standing open problems such as constant-rounds and unconditionally secure protocols for deciding whether a shared number is zero, comparing shared numbers, raising a shared number to a shared exponent and reducing a shared number modulo a shared modulus.

Abstract. In this note, we report on the first large-scale and practical application of multiparty computation, which took place in January 2008. We also report on the novel cryptographic protocols that were used.

The study suggests that bodily distress disorder as defined here may unite many of the functional somatic syndromes and some somatoform disorder diagnoses. Bodily distress may be triggered by stress rather than being distinct diseases of noncerebral pathology.

ICD-10 mental disorders are very prevalent in primary care and there is a high co-occurrence between most disorders. Somatoform disorders, however, more often than not exist without other mental disorders.

These results suggest that rumination about illness plus at least one of five other symptoms form a distinct diagnostic entity performing better than the current DSM-IV hypochondriasis diagnosis. However, these criteria are preliminary, awaiting cross-validation in other subject groups.

The study results suggest that the CMDQ has excellent external validity for use as a diagnostic aid in primary care settings.

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