Encrypted Galaxy S2 to sell - now I can't decrypt to access?

[drsparkman]

I did what I thought was recommended protocol to wipe an Android phone (Samsung Galaxy S2) prior to selling. I encrypted the phone, using a new strong password that I wrote down. Then I performed a factory reset. When it rebooted after that reset, it asked me to "enter password to use encrypted device storage." When I enter the encryption password -- the one that worked at every step of the process until then -- it just says to "try again." I can't access the phone, and I presume no one else will be able to either

What did I do wrong? Did I just create an unusable, unsellable brick?

 

[Antony Guan]

Try going into recovery mode and resetting the whole phone from there

 

[drsparkman]

I can't access recovery mode. The only thing available to me is the black login screen that tells me to "Enter password to use encrypted device storage." And my encryption password does not unlock it.

I've seen scattered references to this problem online. It seems that whatever the cause, this login screen is a dead end. Valid passwords won't work with it.