add note that extracting key from cert is not possible

1 files changed, 3 insertions, 0 deletions

diff --git a/sq-guide.md b/sq-guide.md
index 5117724..12b88ff 100644
--- a/sq-guide.md
+++ b/sq-guide.md
@@ -534,6 +534,9 @@ for it). You need to re-extract the certificate every time you make a
 change to the key that would shared with others: user ids, expiration
 times, sub keys.
 
+Note that while one can extract a certificate from a key, the other
+direction is not possible.
+
 
 ## Sharing one's certificate with others