Enhanced spatial processing of local visual details has been reported in individuals with autism spectrum conditions (ASC), and crowding is postulated to be a mechanism that may produce this ability. However, evidence for atypical crowding in ASC is mixed, with some studies reporting a complete lack of crowding in autism and others reporting a typical magnitude of crowding between individuals with and without ASC. Here, we aim to disambiguate these conflicting results by testing both the magnitude and the spatial extent of crowding in individuals with ASC (N = 25) and age- and IQ-matched controls (N = 23) during an orientation discrimination task. We find a strong crowding effect in individuals with and without ASC, which falls off as the distance between target and flanker is increased. Both the magnitude and the spatial range of this effect were comparable between individuals with and without ASC. We also find typical (uncrowded) orientation discrimination thresholds in individuals with ASC. These findings suggest that the spatial extent of crowding is unremarkable in ASC, and is therefore unlikely to account for the visual symptoms reported in individuals with the diagnosis.This work was supported by a Medical Research Council (MRC) UK grant to JF, a Harvard Society of Fellows grant to CER, and grants from the MRC, the Wellcome Trust, and the Autism Research Trust to SBC. This study was conducted in association with the NIHR CLAHRC EoE and Cambridgeshire and Peterborough NHS Foundation Trust.This is the final version of the article. It first appeared from Association for Research in Vision and Ophthalmology via http://dx.doi.org/10.1167/16.5.1

Freyberg, Jan

Robertson, Caroline E

Baron-Cohen, Simon

Journal of Vision

Using a Key escrow agent in conjunction with Voice over IP (VoIP) communication ensures that law enforcements agencies (LEAs) can retrieve the session key used to encrypt data between two users in a VoIP session. However, the use of a single escrow agent has some drawbacks. A fraudulent request by an evil employee from the LEA can lead to improper disclosure of a session key. After the escrow agent reveals the key this evil person could fabricate data according to his/her needs and encrypt it again (using the correct session key). In this situation the persons involved in the communication session can be accused of crimes that he or she or they never committed. The problems with a single escrow agent becomes even more critical as a failure of the escrow agent can delay or even make it impossible to reveal the session key, thus the escrow agent might not be able to comply with a lawful court order or comply with their escrow agreement in the case of data being released according to this agreement (for example for disaster recovery).This thesis project focused on improving the accessibility and reliability of escrow agents, while providing good security. One such method is based on dividing the session key into m chunks and escrowing the chunks with m escrow agents. Using threshold cryptography the key can be regenerated by gathering any n-out-of-m chunks. The value of m and n may differ according to the role of the user. For a highly sophisticated session, the user might define a higher value for m and n for improved, availability, reliability, and security. For a less confidential or less important session (call), the value of m and n might be smaller. The thesis examines the increased availability and increased reliability made possible by using multiple escrow agents

Azfar, Abdullah

NORA - Norwegian Open Research Archives

Multiple Escrow Agents in VoIP

HSN Open Archive

Using a Key escrow agent in conjunction with Voice over IP (VoIP) communication ensures that law enforcements agencies (LEAs) can retrieve the session key used to encrypt data between two users in a VoIP session. However, the use of a single escrow agent has some drawbacks. A fraudulent request by an evil employee from the LEA can lead to improper disclosure of a session key. After the escrow agent reveals the key this evil person could fabricate data according to his/her needs and encrypt it again (using the correct session key). In this situation the persons involved in the communication session can be accused of crimes that he or she or they never committed. The problems with a single escrow agent becomes even more critical as a failure of the escrow agent can delay or even make it impossible to reveal the session key, thus the escrow agent might not be able to comply with a lawful court order or comply with their escrow agreement in the case of data being released according to this agreement (for example for disaster recovery). This thesis project focused on improving the accessibility and reliability of escrow agents, while providing good security. One such method is based on dividing the session key into M chunks and escrowing the chunks with M escrow agents. Using threshold cryptography the key can be regenerated by gathering any N-out-of-M chunks. The value of M and N may differ according to the role of the user. For a highly sophisticated session, the user might define a higher value for M and N for improved, availability, reliability, and security. For a less confidential or less important session (call), the value of M and N might be smaller. The thesis examines the increased availability and increased reliability made possible by using multiple escrow agents.Med en nyckel förvaringsinstitut som tillsammans med Röst över IP (VoIP) kommunikation säkerställer att brottsbekämpande organ (LEAs) kan hämta sessionsnyckeln används för att kryptera data mellan två användare i en VoIP-session. Däremot har användningen av ett enda förvaringsinstitut visa nackdelar. En bedräglig begäran av en ond arbetstagare från LEA kan leda till otillbörligt röjande av en sessionsnyckel. Efter förvaringsinstitut avslöjar nyckeln detta onda person kunde fabricera uppgifter i enlighet med hans eller hennes behov och kryptera den igen (med rätt sessionsnyckel). I denna situation personer som deltar i kommunikationssession kan anklagas för brott som han eller hon eller de aldrig begått. Problemen med en enda förvaringsinstitut som blir ännu mer kritisk som ett misslyckande av förvaringsinstitut kan försena eller till och med gör det omöjligt att avslöja sessionsnyckeln, vilket förvaringsinstituten kanske inte kan följa en laglig domstolsbeslut eller uppfyller sina depositionsavtalets när det gäller data frisläppas i enlighet med detta avtal (till exempel för katastrofer). Detta examensarbete fokuserar på att förbättra tillgängligheten och tillförlitligheten i spärrade medel, samtidigt som god säkerhet. En sådan metod bygger på att dela upp sessionsnyckeln till M bitar och escrowing i bitar med M förvaringsinstituten. Använda tröskel kryptografi nyckeln kan genereras genom att samla alla N-out-of-M bitar. Värdet på M och N kan variera beroende på användarens roll. För en mycket sofistikerad session kan användaren definiera ett högre värde för M och N för förbättrad tillgänglighet, tillförlitlighet och säkerhet. För en mindre konfidentiell eller mindre viktigt session (telefonsamtal), kan värdet på M och N vara mindre. I avhandlingen analyseras den ökade tillgänglighet och ökad tillförlitlighet möjligt genom att använda flera spärrade medel

Digitala Vetenskapliga Arkivet - Academic Archive On-line

Academic Archive On-line (KTH, Sweden)

Jan Freyberg

Caroline E. Robertson

Simon Baron-Cohen

Crossref