SAJOG • December 2016, Vol. 22, No. 2 42 Background. The intrauterine contraceptive device (IUCD) is a highly effective and safe method of contraception. Prevention of unwanted pregnancies has made its use a matter of national priority in certain countries. Despite numerous advantages and suitability, the uptake of the IUCD is poor. Patients in South Africa (SA) seem to lack knowledge regarding...

A Sybil attack occurs when an adversary controls multiple system identifiers (IDs). Limiting the number of (bad) IDs to a minority is critical for tolerating malicious behavior. popular tool enforcing bad resource burning (RB): verifiable consumption network resource. Unfortunately, typical RB defenses require non-Sybil (good) consume at least as many resources adversary. We present new defense...