Techila Distributed Computing Engine Security Statement

The Techila Server creates the following keys automatically during the Techila Server installation process:

The Techila Administrator key is self-signed and represents the Root Certificate Authority for the TDCE environment. The Techila Administrator key will be automatically used to sign the Techila Server key. This signing process will create the Techila Server certificate.

The Techila Server certificate will be used to authenticate Techila Server to the Techila Workers when the connection is established for the first time. The Techila Workers will store the Administrator certificate on the Worker’s local hard drive when connection to the Techila Server is established for the first time. On subsequent connections Techila Workers will use the Administrator certificate to authenticate the Techila Server.

The Techila Worker is authenticated to the Techila Server with a unique Techila Worker certificate. The Techila Worker certificate is self-signed and is generated automatically when the Techila Worker software is started for the first time. The Worker certificate will be transferred to the Techila Server when connection is established for the first time. The Techila Server will store the Worker certificates in the Techila Server database and use these certificates to validate subsequent connections.

The Techila Worker software uses a dedicated user account on the Worker machine to run all TDCE related processes. On computers with a Windows operating system, the Techila Worker service is authenticated to the operating system with the password defined for the user. On computers with Linux operating systems, the Techila Worker process is started directly using 'su' to run on the dedicated user and no password is used.

This Chapter contains illustrations how the Techila Server and Techila Workers are authenticated. The image below illustrates the situation where the Techila Server is already installed and running and a new Techila Worker is added to the system by installing the Techila Worker software on a computer.

By default, the Techila Server will automatically trust new Techila Worker certificates that are received. When using a non-dedicated computing environment, security can be increased by replacing the automatic trusting mechanism with manual approval performed by the Techila Administrator. Disabling the automatic trusting feature will increase protection against man-in-the-middle attacks, as this will prevent malicious 3rd parties from adding Techila Workers to the TDCE environment.

The image below illustrates the situation where a Techila Worker re-establishes the connection with the Techila Server. This scenario typically occurs if the operating system of the Techila Worker is rebooted.

Each End-User in the TDCE environment has a personal End-User Key, which will be used for authentication when connecting to the Techila Server. These End-User Keys are generated by the Techila Administrator and signed with the Techila Administrator private key. All End-User Keys will need to have a certificate chain leading to the Techila Administrator key. During the key generation process, the End-User certificate will be stored on the Techila Server.

Each End-User will also need a Techila Account, which will be linked with End-User certificate. The Techila Account will be used to configure resource management policies that are applied for the End-User. Authentication to the Techila Web Interface is done using login and password pairs that are defined by the Techila Administrator.

Every Bundle transferred to the Techila Server must be signed with the End-User’s private key. This means that all data transferred to the Techila Server is authenticated with a valid signature. The signature also defines the ownership of the Bundle, which means each Bundle can be traced back to the original creator. Each End-User should store their Techila keystore files in a place where no other can access them.

A copy of each End-User’s certificate with a complete certificate chain can be downloaded from the Techila Web Interface by the Techila Administrator.

Techila Technologies has its own key hierarchy which contains Techila Developer keys. Every Core Bundle is signed with a Techila Developer key. The signature of each Core Bundle is checked on the Techila Server and on the Techila Worker.

This Chapter contains an illustration how the identity of End-Users is authenticated when accessing the TDCE environment.

The process is started when the End-User accesses their user credentials in the password protected keystore file. After opening the keystore file, a network connection will be established with the Techila Server. This connection will validated by sending an encrypted package to the Techila Server and checking if the package can be decrypted with the public part linked to the End-Users Techila Account. If the package can be decrypted, the connection will be marked as valid and the End-User can access the computational environment.

Users are divided into different categories based on the settings of their Techila Accounts and based on type of the Techila key they are using. Techila keys used for authorization are divided in the following categories:

The digital signature algorithm used is SHA1withRSA. Keys can be revoked by using the Techila Keytool (commands "revoke" and "gencrl"). The generated CRL file can be uploaded to the Techila Server from where it is automatically distributed to the Techila Workers.

Techila Accounts can be given the following permissions:

Typically End-Users are always given the 'Bundles' and 'Projects' permissions, which are both required in order to create computational Projects. The 'Projects' permission allows a user to create new Projects, execute them and download the results. The 'Bundle' permission allows a user to create, upload and approve new Bundles, which are used to transfer data used in the computational Projects.

Techila keys are divided into separate hierarchies; one for the customer and one for Techila Technologies. Both of these hierarchies are private and not linked to any public Certificate Authority. The figure below illustrates the two separate hierarchies.

The functionality associated with each key type is explained in the following Chapters.

The Techila Worker software is installed and executed using a dedicated user account, which does not have administrative permissions.

This dedicated user account requires access to the following directories:

Access to any other directory should be restricted.

When the Techila Worker software is installed on a computer with a Windows operating system, the installation process (by default) creates a dedicated user account with the required access rights. This account is not allowed to log on to the system interactively.

On computers with a Linux operating system, the dedicated user account is manually created by the administrator. The dedicated user account should be given access to the directories listed above.

Bundles are used to transfer data in a TDCE environment. Bundles are typically transferred between the following peers in a TDCE environment:

Before Bundles are transferred, a secure TLS channel is created between the peers based on the authentication mechanisms described in Chapters Techila Server and Techila Worker Authentication and End-User and Techila Server Authentication. After peers have been authenticated and a TLS channel has been created, Bundles can be transferred.

After a Bundle has been transferred, each receiving peer will validate the Bundle signature. If the signature validation fails, the Bundle will be rejected and the transferred file will be deleted. This means that the signature validation is two-tiered, which increases data management security compared to single-tiered architectures. The Bundle transfer and signature validation process is illustrated below. However, in secure environments such as clusters, this checking can be disabled for performance reasons.