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Software Defined Networks (SDN) facilitate network management by decoupling the data plane which forwards packets using efficient switches from the control plane by leaving the decisions on how packets should be forwarded to a (centralized) controller. However, due to limitations on the number of forwarding rules a switch can store in its TCAM memory, SDN networks have been subject to saturation and TCAM exhaustion attacks where the attacker is able to deny service by forcing a target switch to install a great number of rules. An underlying assumption is that these attacks are carried out by sending a high rate of unique packets. This paper shows that this assumption is not necessarily true and that SDNs are vulnerable to Slow TCAM exhaustion attacks (Slow-TCAM). We analyse this attack arguing that existing defenses for saturation and TCAM exhaustion attacks are not able to mitigate Slow-TCAM due to its relatively low traffic rate. We then propose a novel defense called SIFT based on selective strategies demonstrating its effectiveness against the Slow-TCAM attack.

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Introduction: Vascular access (VA) in hemodialysis (HD) is essential to end-stage renal disease (ESRD) patients survival. Unfortunately, after some years in HD program, a significant number of patients may develop VA failure for many reasons. In this situation, arterial venous fistula (AVF) confection or catheters placement in traditional vascular sites (jugular, femoral or subclavian) are not feasible. In this scenario, translumbar tunneled dialysis catheter (TLDC) may be a salvage option. Objectives: To describe placement technic, complications, and patency of 12 TLDC. Methods: A retrospective study was performed to analyze 12 TLDC placement in an angiography suite using fluoroscopic guidance at the University Hospital of the Rio Grande do Norte Federal University from January 2016 to October 2017. The data collected of the total procedures performed consisted of demographic characteristics, success rates, observed complications, patient survival, and catheter patency. Results: All 12 TLDC were placed with success; there were only 2 significant periprocedure complications (major bleeding and extubation failure); 41.6% of patients presented a catheter-related first infection after 98 ± 72.1 (6-201) days, but catheter withdrawal was not necessary, mean total access patency was 315.5 (range 65 - 631) catheter-days, and catheter patency at 3, 6 and 12 months was 91 %, 75%, and 45%. Conclusion: TLDC is an option for patients with VA failure, improving survival and acting as a bridge for renal transplantation.

O objetivo deste trabalho é mostrar a possibilidade da aplicação da economia comportamental como catalizadora de resultados em uma política pública. Primeiramente, é preciso mostrar a existência da racionalidade limitada que pode interferir no processo de escolha dos indivíduos. Ademais, é importante legitimar as interferências governamentais que visem a correção de comportamentos sem o uso da coerção. Como estudo de caso, será utilizado o quadro de doação de medula óssea no Brasil. Após a aprovação da lei 13.656/2018, que concede isenção de pagamento da taxa de inscrição de concursos públicos para os cadastrados como doadores de medula, há uma possibilidade de agravamento no quadro de desistências de doação. Dado que a recusa pode ser fatal ao paciente à espera do transplante, será importante a formulação de políticas públicas que promovam o cadastramento consciente, sendo os conhecimentos desenvolvidos pela teoria comportamental um candidato viável.

Timing side-channel vulnerabilities constitute a serious threat against privacy and confidentiality of data. In this article, we study the effects of bucketing, a previously proposed mitigation technique against timing side channels. We present two implementations of bucketing that reside at the application and at the kernel level, respectively. We experimentally evaluate the effectiveness of these implementations in a setting with non-deterministic timing behavior, a practically relevant setting that has not been studied before. Our results show that the impact of non-deterministic timing behavior is substantial. The bucket boundaries cannot be established sharply and this reduces the effectiveness of bucketing. Nevertheless, bucketing still provides a significant reduction of side-channel capacity.