Twotypesofnewsubliminalchannelsareconstructedrespectivelybasedonprovablesecurepublickeycryptosystemsandidentityrecognitioninsomenetworkapplications.Researchshowsthattherearesomenewcharacteristicswhichareinfavorofcovertcommunicationinourconstructions.Itishardtomakethesubliminalchannelsfree,andthechannelshavelargecapacityandhightransmissionefficiency.Wealsopointoutthatthehardnesstomakethechannelsfreeisdisadvantageoustothewardenwhotriestothwartthecovertcommunication.