A tamper respondent system having: a physical volume containing an electronic device to be protected; an at least partially conductive surface proximate to the electronic device; and a tamper respondent sensor over the electronic device (the sensor comprising: a flexible, dielectric substrate; conductive traces on the substrate; a porous insulating layer having pores over the conductive traces; and adhesive within said pores of said porous insulating layer), wherein the adhesive is in contact with both the substrate and the at least partially conductive surface through the porous insulating layer.