Comment # 20 on bug 1175908 from Harald Koenig

(In reply to Takashi Iwai from comment #15)
> I dunno, it depends on how it was encrypted.  We may check the crypt entries
> in the working case.

how can I find out how my partition is encrypted ?
maybe this can help (running 5.3.12): 

# cryptsetup status cr_sda5 
/dev/mapper/cr_sda5 is active and is in use.
  type:    LUKS1
  cipher:  aes-cbc-essiv:sha256
  keysize: 256 bits
  key location: dm-crypt
  device:  /dev/sda5
  sector size:  512
  offset:  4096 sectors
  size:    1048571904 sectors
  mode:    read/write