README.md: Fix link to "What class should I use?"

README.md

@@ -9,7 +9,7 @@ Secrets hold sensitive information
 The Secret interface manages limited time access to a secret and securely erases the secret when no longer needed.
 
 Multiple `Secret` classes exist.  Most of the time you shouldn't need to change the `Secret` type - the cryptographic library should have sane defaults.
-If you have a high security or high performance application see [which secret type should I choose?]()
+If you have a high security or high performance application see [which secret type should I use?](https://didactic-drunk.github.io/crypto-secret.cr/main/Crypto/Secret.html)
 
 Secret providers may implement additional protections via:
 * `#noaccess`, `#readonly` or `#readwrite`

src/crypto-secret/key.cr

@@ -1,7 +1,7 @@
 require "./bidet"
 
 module Crypto::Secret
-  # Use this class for holding small amounts of sensitive data such as encryption keys
+  # Use this class for holding small amounts of sensitive data such as crypto keys
   #
   # Underlying implentation subject to change
   #

src/crypto-secret/secret.cr

@@ -7,12 +7,12 @@ require "./class_methods"
 #
 # For all other applications use a preexisting class that includes `Crypto::Secret`
 #
-# # Which class should I use?
+# ## Which class should I use?
-# * Crypto::Secret::Key - Use with small (<= 4096 bytes) keys
+# * `Crypto::Secret::Key` - Use with small (<= 4096 bytes) keys
-# * Crypto::Secret::Large - Use for decrypted data that may stress mlock limits
+# * `Crypto::Secret::Large` - Use for decrypted data that may stress mlock limits
-# * Crypto::Secret::Not - Won't get wiped but 0 overhead.  Only use when you're sure the data isn't secret
+# * `Crypto::Secret::Not` - Only use when you're sure the data isn't secret.  0 overhead.  No wiping.
 #
-# Other shards may provide additional `Secret` types (sodium.cr)
+# Other shards may provide additional `Secret` types ([sodium.cr](https://github.com/didactic-drunk/sodium.cr))
 @[Experimental]
 module Crypto::Secret
   class Error < Exception
@@ -112,7 +112,7 @@ module Crypto::Secret
     end
   end
 
-  def wipe_impl(slice : Bytes) : Nil
+  protected def wipe_impl(slice : Bytes) : Nil
     slice.wipe
   end
 end