Generic Architecture and Semiconductor Intellectual Property Cores for Avanced Encryption Standard Cryptography

A generic architecture for implementing the advanced encryption standard (AES) encryption algorithm in silicon is proposed. This allows the instantiation of a wide range of chip specifications, with these taking the form of semiconductor intellectual property (IP) cores. Cores implemented from this architecture can perform both encryption and decryption and support four modes of operation: (i) electronic codebook mode; (ii) output feedback mode; (iii) cipher block chaining mode; and (iv) ciphertext feedback mode. Chip designs can also be generated to cover all three AES key lengths, namely 128 bits, 192 bits and 256 bits. On-the-fly generation of the round keys required during decryption is also possible. The general, flexible and multi-functional nature of the approach described contrasts with previous designs which, to date, have been focused on specific implementations. The presented ideas are demonstrated by implementation in FPGA technology. However, the architecture and IP cores derived from this are easily migratable to other silicon technologies including ASIC and PLD and are capable of covering a wide range of modem communication systems cryptographic requirements. Moreover, the designs produced have a gate count and throughput comparable with or better than the previous one-off solutions.

Substance Use Behaviours of Young People with A Moderate Learning Disability: A longitudinal analysis

Substance use behaviours of young people attending a special school are reported over a four year period from the age of 12-16 years. The paper investigated these behaviours by surveying a cohort of young people with a statement for moderate learning disabilities annually during the last four years of compulsory schooling. The findings show that these young people consistently reported lower levels of tobacco, alcohol and cannabis use compared with those attending mainstream school. No other illicit drug use was reported. The potential implications of these findings are discussed in relation to the context and timing of targeted substance education and prevention initiatives for young people with moderate learning disability attending a special school.

The mental health needs of people with a learning disability detained in police custody

Few research studies examine the prevalence or mental health needs of people with a Learning Disability (LD) detained in police custody. This paper describes the population of detainees with an LD who presented to an inner city inter-agency police liaison service during a three-year period. Two forensically trained Community Mental Health Nurses (CMHNs) screened all custody record forms (n=9014) for evidence of a mental health problem or LD. The CMHNs interviewed positively screened detainees (n=1089) using a battery of measures designed to assess mental health status, risk-related behaviour and alcohol or drug abuse. Almost one-in-ten of those interviewed (95/1089) were judged to have a possible or definite LD. Fifty-two per cent were cases on the General Health Questionnaire (GHQ) whilst 61% attained 'above threshold' Brief Psychiatric Rating Scale (BPRS) scores. The majority (63%) had a history of causing harm to others while 56 per cent had a history of self-harm. More than half (56%) regularly consumed harmful levels of alcohol while one-in-four (27%) reported abusing drugs. Higher than expected numbers of detainees have a learning disability and most have complex mental health needs. A police liaison service offers a way of identifying people with LD and connecting them with appropriate health and social care agencies.

Costing the hospital-based process of resettling people with learning disability in the community

Objectives: Much has been written about the costs and cost-effectiveness of community care for people with learning disabilities resettled from long stay hospital care. However, comparatively little has been published about the cost of hospital services relating to the preparatory process before eventual resettlement and the disengagement of formal, sustained input from hospital staff. This study describes and costs the input provided by a hospital based multi-disciplinary team into the resettlement of adults with learning disabilities, from long stay wards in Muckamore Abbey Hospital in Northern Ireland between 1996 and 1999 (n = 71).