diff --git a/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/Challenge.java b/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/Challenge.java
index e24acd10..57b6186b 100644
--- a/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/Challenge.java
+++ b/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/Challenge.java
@@ -190,15 +190,6 @@ public class Challenge extends AcmeResource {
         }
 
         data = json;
-        authorize();
-    }
-
-    /**
-     * Callback that is invoked when the challenge is supposed to compute its
-     * authorization data.
-     */
-    protected void authorize() {
-        // Does nothing here...
     }
 
     /**
diff --git a/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TlsSni02Challenge.java b/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TlsSni02Challenge.java
index 03404655..66c4513e 100644
--- a/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TlsSni02Challenge.java
+++ b/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TlsSni02Challenge.java
@@ -28,9 +28,6 @@ public class TlsSni02Challenge extends TokenChallenge {
      */
     public static final String TYPE = "tls-sni-02";
 
-    private String subject;
-    private String sanB;
-
     /**
      * Creates a new generic {@link TlsSni02Challenge} object.
      *
@@ -46,7 +43,8 @@ public class TlsSni02Challenge extends TokenChallenge {
      * The CA will send the SNI request against this domain.
      */
     public String getSubject() {
-        return subject;
+        String tokenHash = hexEncode(sha256hash(getToken()));
+        return tokenHash.substring(0, 32) + '.' + tokenHash.substring(32) + ".token.acme.invalid";
     }
 
     /**
@@ -54,7 +52,8 @@ public class TlsSni02Challenge extends TokenChallenge {
      * certificate.
      */
     public String getSanB() {
-        return sanB;
+        String kaHash = hexEncode(sha256hash(getAuthorization()));
+        return kaHash.substring(0, 32) + '.' + kaHash.substring(32) + ".ka.acme.invalid";
     }
 
     @Override
@@ -62,15 +61,4 @@ public class TlsSni02Challenge extends TokenChallenge {
         return TYPE.equals(type);
     }
 
-    @Override
-    protected void authorize() {
-        super.authorize();
-
-        String tokenHash = hexEncode(sha256hash(getToken()));
-        subject = tokenHash.substring(0, 32) + '.' + tokenHash.substring(32) + ".token.acme.invalid";
-
-        String kaHash = hexEncode(sha256hash(getAuthorization()));
-        sanB = kaHash.substring(0, 32) + '.' + kaHash.substring(32) + ".ka.acme.invalid";
-    }
-
 }
diff --git a/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TokenChallenge.java b/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TokenChallenge.java
index 5e80ebc8..e406756d 100644
--- a/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TokenChallenge.java
+++ b/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TokenChallenge.java
@@ -33,8 +33,6 @@ public class TokenChallenge extends Challenge {
     protected static final String KEY_TOKEN = "token";
     protected static final String KEY_KEY_AUTHORIZATION = "keyAuthorization";
 
-    private String authorization;
-
     /**
      * Creates a new generic {@link TokenChallenge} object.
      *
@@ -59,21 +57,12 @@ public class TokenChallenge extends Challenge {
     }
 
     /**
-     * Gets the authorization.
-     */
-    protected String getAuthorization() {
-        return authorization;
-    }
-
-    /**
-     * Computes the authorization string.
+     * Returns the authorization string.
      * <p>
      * The default is {@code token + '.' + base64url(jwkThumbprint)}. Subclasses may
      * override this method if a different algorithm is used.
-     *
-     * @return Authorization string
      */
-    protected String computeAuthorization() {
+    protected String getAuthorization() {
         try {
             PublicKey pk = getSession().getKeyPair().getPublic();
             PublicJsonWebKey jwk = PublicJsonWebKey.Factory.newPublicJwk(pk);
@@ -85,10 +74,4 @@ public class TokenChallenge extends Challenge {
         }
     }
 
-    @Override
-    protected void authorize() {
-        super.authorize();
-        authorization = computeAuthorization();
-    }
-
 }