In an approach for securing data, a processor publishes a traditional public key in a traditional certificate and a PQC public key in a PQC certificate. A processor encrypts data with a hybrid shared secret, the hybrid shared secret generated with a key derivation function by using a traditional shared secret based on the traditional public key and a PQC shared secret based on the PQC public key. A processor decrypts the data with the hybrid shared secret based on a traditional private key and a PQC private key. A processor signs the data with a traditional signature followed by a PQC signature.