Of course, the use of HPC clusters requires additional configuration, which is relevant to explain further. The key element of this process is the initiation of a secure shell (SSH) connection to the remote HPC cluster. When adding a new cluster access in CalcUS, a public-private key pair will be generated using standard cryptographic protocols. The public key must be added manually by the user in his list of allowed keys on the HPC cluster. The private key can then act as a surrogate for the user password, allowing the platform to access the user account on the remote HPC cluster. For security reasons, this private key is encrypted by a password chosen by the user, which is not saved anywhere. Thus, the platform can only connect to the HPC cluster when the user enters this password and initiates the connection. This SSH connection can be closed by the user at any moment. All these measures ensure that the actual password of the user account on the HPC cluster is never used or saved in the CalcUS infrastructure, and that only the user can make use of the private key and allow connection to his account.