It is certainly important to prevent “backdoors” from being built and kept open, but it should never mean that the “front entrance” is less important.
It is very difficult to detect a thief who breaks into a house if he has a passkey, unless he leaves the house visibly in a mess. So is a cyber attacker who has obtained a password of a target person. Intrusions through the “cyber front entrance” by stolen passwords are hardly noticed, resulting in fewer records of intrusion attacks and fewer discussions.
People who are conscious of the significance of this vulnerability and advocate rigid password policies seldom look at a very basic fact; the number of accounts that require passwords is said to be 20 ~ 26 and still keep increasing, whereas the number of passwords that humans can keep remembering is said to be no more than 3 ~ 5 with no hope of increasing.
I am of the belief that it is an urgent task to fill this ever increasing gap, and I propose that we could make use of episodic/autobiographic image memory in order to make the protection of the cyber front entrance (=remembered passwords) more secure while keeping availability high.
Should you be interested you would be invited to my earlier discussions posted at http://mneme.blog.eonet.jp/default/linkedin_discussion/