diff --git a/Makefile.PL b/Makefile.PL
index 6418f73d4..e52a785df 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -8,6 +8,7 @@ requires(
 'Apache::Request' => 0, 
 'AppConfig' => 0, 
 'Clone' => 0, 
+'Crypt::Eksblowfish::Bcrypt' => 0,
 'DBI' => 0, 
 'DBD::Pg' => 1.22,
 'Data::ICal' => '0.16', # Data::ICal::Entry::Event
diff --git a/lib/Act/Auth.pm b/lib/Act/Auth.pm
index e2d6b339c..66ceecd9e 100644
--- a/lib/Act/Auth.pm
+++ b/lib/Act/Auth.pm
@@ -3,7 +3,6 @@ package Act::Auth;
 use strict;
 use Apache::AuthCookie;
 use Apache::Constants qw(OK);
-use Digest::MD5 ();
 
 use Act::Config;
 use Act::User;
@@ -55,9 +54,7 @@ sub authen_cred ($$\@)
     $user or do { $r->log_error("$prefix Unknown user"); return undef; };
 
     # compare passwords
-    my $digest = Digest::MD5->new;
-    $digest->add(lc $sent_pw);
-    $digest->b64digest() eq $user->{passwd}
+    Act::Util::verify_password(lc $sent_pw, $user->{passwd})
         or do { $r->log_error("$prefix Bad password"); return undef; };
 
     # user is authenticated - create a session
diff --git a/lib/Act/Handler/User/ChangePassword.pm b/lib/Act/Handler/User/ChangePassword.pm
index 94fb296de..7d598c6c7 100644
--- a/lib/Act/Handler/User/ChangePassword.pm
+++ b/lib/Act/Handler/User/ChangePassword.pm
@@ -9,7 +9,6 @@ use Act::Template::HTML;
 use Act::User;
 use Act::Util;
 use Act::TwoStep;
-use Digest::MD5 ();
 
 my $form = Act::Form->new(
   required => [qw(newpassword1 newpassword2)],
@@ -64,9 +63,7 @@ sub handler
         my ($token, $token_data);
         if ($Request{user}) { # 
             # compare passwords
-            my $digest = Digest::MD5->new;
-            $digest->add(lc $fields->{oldpassword});
-            $digest->b64digest() eq $Request{user}{passwd}
+            Act::Util::verify_password(lc $fields->{oldpassword}, $Request{user}{passwd})
                 or do { $ok = 0; $form->{invalid}{oldpassword} = 1; };
         }
         else { # must have a valid twostep token if not logged in
@@ -91,7 +88,7 @@ sub handler
             }
             # update user
             $Request{user}->update(
-                passwd => Act::Util::crypt_password( $fields->{newpassword1} )
+                passwd => Act::Util::crypt_password( $fields->{newpassword1}, Act::Util::gen_salt() )
             );
 
             # redirect to user's main page
diff --git a/lib/Act/Util.pm b/lib/Act/Util.pm
index 0f4069a03..d6a541745 100644
--- a/lib/Act/Util.pm
+++ b/lib/Act/Util.pm
@@ -7,6 +7,7 @@ use Apache::AuthCookie;
 use DateTime::Format::Pg;
 use DBI;
 use Digest::MD5 ();
+use Crypt::Eksblowfish::Bcrypt qw(bcrypt en_base64);
 use Unicode::Normalize ();
 use URI::Escape ();
 
@@ -148,15 +149,47 @@ sub gen_password
 {
     my $clear_passwd = $pass[ rand @pass ];
     $clear_passwd =~ s/([vc])/$grams{$1}[rand@{$grams{$1}}]/g;
-    return ($clear_passwd, crypt_password( $clear_passwd ));
+    return ($clear_passwd, crypt_password( $clear_passwd, gen_salt() ));
+}
+
+sub gen_salt
+{
+    # bcrypt cost is between 1 and 31
+    my $cost = 10;
+
+    # salt must be 16 bytes long at most.
+    my $salt;
+    $salt .= ('.', '/', 0..9, 'A'..'Z', 'a'..'z')[rand 64] for 1..16;
+
+    # bcrypt uses a non-standard base64 encoding and cost is padded
+    return join('$', '', '2a', sprintf("%02d", $cost), en_base64($salt));
 }
 
 sub crypt_password
 {
-    my $digest = Digest::MD5->new;
-    $digest->add(shift);
-    return $digest->b64digest();
+    my ($plaintext, $salt) = @_;
+
+    # crypt using MD5 digest for old passwords
+    if (!defined $salt || $salt !~ /^\$\d/) {
+        my $digest = Digest::MD5->new;
+        $digest->add($plaintext);
+        return $digest->b64digest();
+    }
+
+    # Eksblowfish
+    return bcrypt($plaintext, $salt)
+        if $salt =~ /^\$2a?\$\d+\$/;
+
+    # crypt(3)
+    return crypt($plaintext, $salt);
 }
+
+sub verify_password
+{
+    my ($clear_passwd, $crypt_passwd) = @_;
+    return crypt_password( $clear_passwd, $crypt_passwd ) eq $crypt_passwd;
+}
+
 sub create_session
 {
     my $user = shift;
diff --git a/t/05util.t b/t/05util.t
index d19c80cd8..3713d1055 100644
--- a/t/05util.t
+++ b/t/05util.t
@@ -5,7 +5,7 @@ use utf8;
 use DateTime;
 use Test::MockObject;
 use constant NBPASS => 100;
-use Test::More tests => 79 + 5 * NBPASS;
+use Test::More tests => 80 + (6+2) * NBPASS;
 use Act::Config;
 
 BEGIN { use_ok('Act::Util') }
@@ -62,7 +62,7 @@ while (my ($u, $args, $expected) = splice(@t, 0, 3)) {
     is(self_uri(%$args), $expected);
 }
 
-# gen_password
+# gen_password and verify_password
 my %seen;
 for (1..NBPASS) {
     my ($clear, $crypted) = Act::Util::gen_password();
@@ -70,8 +70,21 @@ for (1..NBPASS) {
     ok(!$seen{$clear}++);
     ok($crypted);
     like($clear,   qr/^[a-z]+$/);
-    like($crypted, qr/^\S+$/);
+    like($crypted, qr/^\$\S+\$\S+$/);
+    ok( Act::Util::verify_password($clear, $crypted) );
 }
+
+# gen_salt
+%seen = ();
+for (1..NBPASS) {
+    my $salt = Act::Util::gen_salt();
+    ok($salt);
+    ok(!$seen{$salt}++);
+}
+
+# verify_password and crypt_password without salt
+ok( Act::Util::verify_password('f00bar', Act::Util::crypt_password('f00bar')) );
+
 # date_format
 use utf8;
 $Request{language} = 'fr';