A plastic card for easy to remember strong passwords

We've got you covered: https://www.qwertycards.com/frequent_questions.html#lost_sto...

Every card ships with a letter showing the only unique copy of the card.

This would actually be very useful for my Google and LastPass password. I have everything else in my LastPass manager, but it is always trying to get into my google account from different places is difficult, so I have a rememberable password for both.

This would let me keep a much more secure password for both.

This is a substitution cipher and it's not very secure. Consider what we can do if we compromise the Amazon password that's given as an example on the website:

   sh(/J3HqAfQsu..u.rqf

Since the password came from Amazon, we know that the last 6 characters are "Amazon," which tells us that:

  . = A
  u = M
  r = Z
  q = O
  f = N

Now we can start attacking the codeword, which are the characters between the 8-character "space bar code" and the website name:

  AfQsu.

Using the letters we already know, we can determine that the codeword is:

  _N__MA

It's probably a dictionary word, and we know that the blank spaces don't correspond to any of the letters we already know. According to the following command:

  grep '^[^amzon]n[^amzon][^amzon]ma$' 

...the only possible codeword is "engima," so now we know that:

  A = E
  Q = G
  s = I

Combine with another compromised password, and we're coming dangerously close to being able to generate a password for any arbitrary website.

Edit: I agree with the replies that this is an unlikely attack considering how passwords are typically compromised. And it's probably better than how most people choose passwords. But the website claims that this generates "very strong passwords," which is nonsense.