Want to change the tarsnap.key file?
Check out this manual: https://www.acunote.com/blog/2012/02/tarsnap-key-rotation-with-tarsnap-recrypt-and-tarsnap-keyregen.html
Especially this part of code is useful:
# create new key
tarsnap-keyregen --keyfile ~/tarsnap/keys/server.new.key \
--oldkey ~/tarsnap/keys/server.old.key \
--user [email protected] --machine server
# run recrypt. This can take a long time (days), and final delete
# transaction will fail because of server cron jobs that will happen
# in the meantime
tarsnap-recrypt --oldkey ~/tarsnap/keys/server.old.key \
--oldcachedir ~/tarsnap/cache/server.old \
--newkey ~/tarsnap/keys/server.new.key \
--newcachedir ~/tarsnap/cache/server.new
You can find the location of your tarsnap key file and cache folder with:
find / -name tarsnap.key
find / -name tarsnap-cache