mention SLIP-0039 secret splitting

howto/openpgp.md

@@ -869,6 +869,8 @@ key.
         tr -dc '[:alnum:]' < /dev/urandom | head -c 30 ; echo
         ssss-split -t 3 -n 5
 
+    Note: consider using SLIP-0039 instead, see below.
+
  5. export the secrets and create the encrypted archive:
 
         mkdir openpgp-ssss-backup-$FINGERPRINT
@@ -1091,6 +1093,25 @@ You will need to adapt this to your purposes.
 
 ### Other approaches
 
+I am considering a more standard secret sharing scheme based on
+[SLIP-039](https://github.com/satoshilabs/slips/blob/master/slip-0039.md), established in the Bitcoin community, but that is
+applicable everywhere. The [python-shamir-mnemonic implementation](https://github.com/trezor/python-shamir-mnemonic),
+for example, provides human-readable secrets:
+
+```
+anarcat@angela:~> shamir create 3of5
+Using master secret: 608e920fc59a6cf2d23bcfe6cb889771
+Group 1 of 1 - 3 of 5 shares required:
+yield pecan academic acne body teacher elder twin detect vegan solution maiden home switch dryer member purple voice acquire username
+yield pecan academic agree ajar cause critical leader admit viral taxi puny curious sled often satoshi lips afraid stadium froth
+yield pecan academic amazing blanket decision crystal vexed trial fitness shaped timber helpful beard strategy curious episode sniff object heat
+yield pecan academic arcade alcohol vampire employer package tactics extra window sympathy darkness adapt laundry genius laser closet example ruler
+yield pecan academic axle aquatic have racism debris spew dive human thumb weapon satoshi curly lobe lecture visitor example alarm
+```
+
+Notice how the first three words are the same in all tokens? That's
+also useful to identify the secret itself...
+
 Note that if you are comfortable sharing all your secret keys with
 those peers, a simpler procedure is to re-encrypt your own backup with
 a symmetric key instead of your Yubikey encryption key. This is much