3 ms·Is sms channel really secure? Isn't it a plain text channel, as opposed to an unencrypted channel?by ybaumes 13y agoIs sms channel really secure? Isn't it a plain text channel, as opposed to an unencrypted channel?yuvadam 13y agoSMS is encrypted on GSM control channels using the broken A5/1 stream cipher which has well-known weaknesses.anaphor 13y agoand the base station can _disable_ encryption completely without any warning given to the cellphone user.