diff --git a/pym/core/server/create_cert.py b/pym/core/server/create_cert.py
index 378b317..3603ac4 100644
--- a/pym/core/server/create_cert.py
+++ b/pym/core/server/create_cert.py
@@ -105,7 +105,7 @@ def makeRequest(pubkey, pkey, serv_host, port):
     extstack = X509.X509_Extension_Stack()
     extstack.push(ext1)
     req.add_extensions(extstack)
-    req.sign(pkey, 'md5')
+    req.sign(pkey, 'sha256')
     return req
 
 class CreateCertError(Exception):
@@ -140,7 +140,7 @@ def create_selfsigned_ca(dn_data, keyfile, certfile):
             #crypto.X509Extension(b'keyUsage', False, b'keyCertSign, cRLSign'),
             crypto.X509Extension(b'subjectKeyIdentifier', False, b'hash', subject=ca)])
         ca.add_extensions([crypto.X509Extension(b'authorityKeyIdentifier', False, b'keyid:always',issuer=ca)])
-        ca.sign(pkey, 'sha1')
+        ca.sign(pkey, 'sha256')
 
         with writeFile(certfile, binary=True) as f:
             f.write(crypto.dump_certificate(crypto.FILETYPE_PEM, ca))