diff --git a/impl/core/src/main/java/br/gov/frameworkdemoiselle/security/Authenticator.java b/impl/core/src/main/java/br/gov/frameworkdemoiselle/security/Authenticator.java
index 3445e53..3fc9e06 100644
--- a/impl/core/src/main/java/br/gov/frameworkdemoiselle/security/Authenticator.java
+++ b/impl/core/src/main/java/br/gov/frameworkdemoiselle/security/Authenticator.java
@@ -46,22 +46,34 @@ import java.io.Serializable;
 public interface Authenticator extends Serializable {
 
 	/**
-	 * Executes the necessary steps to authenticate an user.
+	 * Executes the necessary steps to authenticate an user. After this call, {@link #getUser()} must return
+	 * the currently authenticated user and it will return <code>null</code> if the authentication process fails.
 	 * 
-	 * @throws AuthenticationException
-	 *             When the authentication process fails, this exception is thrown.
+	 * @throws InvalidCredentialsException
+	 *             You should throw this exception when the informed credentials are invalid. 
+	 * @throws Exception
+	 *             If the underlying authentication mechanism throwns any other exception,
+	 *             just throw it and leave the security context implementation to handle it.
 	 */
-	void authenticate();
+	void authenticate() throws Exception;
 
 	/**
-	 * Executes the necessary steps to unauthenticate an user.
+	 * Executes the necessary steps to unauthenticate an user. After this call, {@link #getUser()} must return <code>null</code>.
+	 * 
+	 * @throws Exception
+	 *             If the underlying authentication mechanism throwns any other exception,
+	 *             just throw it and leave the security context implementation to handle it.
 	 */
-	void unAuthenticate();
+	void unauthenticate() throws Exception;
 
 	/**
 	 * Returns the currently authenticated user.
 	 * 
-	 * @return the user currently authenticated
+	 * @return the user currently authenticated, or <code>null</code> if there is no
+	 * authenticated user.
+	 * 
+	 * @see #authenticate()
+	 * @see #unauthenticate()
 	 */
 	User getUser();
 }
diff --git a/impl/core/src/main/java/br/gov/frameworkdemoiselle/security/Authorizer.java b/impl/core/src/main/java/br/gov/frameworkdemoiselle/security/Authorizer.java
index aab7712..f964797 100644
--- a/impl/core/src/main/java/br/gov/frameworkdemoiselle/security/Authorizer.java
+++ b/impl/core/src/main/java/br/gov/frameworkdemoiselle/security/Authorizer.java
@@ -51,8 +51,11 @@ public interface Authorizer extends Serializable {
 	 * @param role
 	 *            role to be checked
 	 * @return {@code true} if the user has the role
+	 * @throws Exception
+	 *             If the underlying permission checking mechanism throwns any other exception, just throw it and leave
+	 *             the security context implementation to handle it.
 	 */
-	boolean hasRole(String role);
+	boolean hasRole(String role) throws Exception;
 
 	/**
 	 * Checks if the logged user has permission to execute an specific operation on a specific resource.
@@ -62,7 +65,10 @@ public interface Authorizer extends Serializable {
 	 * @param operation
 	 *            operation to be checked
 	 * @return {@code true} if the user has the permission
+	 * @throws Exception
+	 *             If the underlying permission checking mechanism throwns any other exception, just throw it and leave
+	 *             the security context implementation to handle it.
 	 */
-	boolean hasPermission(String resource, String operation);
+	boolean hasPermission(String resource, String operation) throws Exception;
 
 }
--
libgit2 0.21.2