An apparatus to establish secure communications comprising: a processor component, arranged to process: a control routine comprising a signal component and a bioelectric component; the signal component for execution by the processor component to compare a signal characteristic of a security test signal to a known signal characteristic of the security test signal to derive a bioelectric characteristic, the security test signal received via a tissue; the bioelectric component for execution by the processor component to determine whether to allow transmission of data through the tissue based on the bioelectric characteristic, characterized in that the bioelectric component is to compare the bioelectric characteristic to a first plurality of expected bioelectric characteristics and to allow transmission of the data through the tissue based on the bioelectric characteristic matching a first expected bioelectric characteristic of the first plurality of expected bioelectric characteristics, each expected bioelectric characteristic of the first plurality of expected bioelectric characteristics associated with a different location on a body comprising the tissue at which a body-carried device may be disposed to transmit the security test signal. a processor component, arranged to process: a control routine comprising a signal component and a bioelectric component; the signal component for execution by the processor component to compare a signal characteristic of a security test signal to a known signal characteristic of the security test signal to derive a bioelectric characteristic, the security test signal received via a tissue; the bioelectric component for execution by the processor component to determine whether to allow transmission of data through the tissue based on the bioelectric characteristic, characterized in that the bioelectric component is to compare the bioelectric characteristic to a first plurality of expected bioelectric characteristics and to allow transmission of the data through the tissue based on the bioelectric characteristic matching a first expected bioelectric characteristic of the first plurality of expected bioelectric characteristics, each expected bioelectric characteristic of the first plurality of expected bioelectric characteristics associated with a different location on a body comprising the tissue at which a body-carried device may be disposed to transmit the security test signal. a control routine comprising a signal component and a bioelectric component; the signal component for execution by the processor component to compare a signal characteristic of a security test signal to a known signal characteristic of the security test signal to derive a bioelectric characteristic, the security test signal received via a tissue; the bioelectric component for execution by the processor component to determine whether to allow transmission of data through the tissue based on the bioelectric characteristic, characterized in that the bioelectric component is to compare the bioelectric characteristic to a first plurality of expected bioelectric characteristics and to allow transmission of the data through the tissue based on the bioelectric characteristic matching a first expected bioelectric characteristic of the first plurality of expected bioelectric characteristics, each expected bioelectric characteristic of the first plurality of expected bioelectric characteristics associated with a different location on a body comprising the tissue at which a body-carried device may be disposed to transmit the security test signal.