Abstract: Methods, devices and systems for encryption and decryption of data. Encryption is performed using one or more passes of Dirichlet convolution involving an encryption key, which may be combined with other invertible operations. Decryption is performed using a corresponding number of passes of a Dirichlet inverse operation using a decryption key, and the corresponding invertible operations.

Abstract: Cutting devices and associated methods are described. In one aspect, a cutting device includes an annular support body defining an axial space into which a pipe to be cut can be inserted, the body formed of a rigid material and including a blade-bearing portion and a non-blade-bearing portion, wherein the blade-bearing portion is secured to the non-blade-bearing portion by a hinge mechanism allowing the two portions to be movable between an open position in which a pipe can be inserted, and a closed position in which the pipe is engaged by the body, wherein a part of the blade-bearing portion spaced from the hinge mechanism includes a blade that protrudes radially inwards of the body, such that in use the urging of the two portions towards the closed position urges the pipe against the blade so that rotation of the cutting device around the pipe cuts the pipe.

Abstract: A cutting device for cutting a pipe of a set diameter comprises an annular support body defining an axial space into which a pipe to be cut can be inserted. The annular support body is formed of a rigid material and comprises a blade-bearing portion and a non-blade-bearing portion. The blade-bearing portion is secured to the non-blade-bearing portion by a hinge mechanism allowing the two portions to be movable between an open position, in which the pipe can be inserted and removed from the body, and a closed position, in which the pipe, once inserted, is engaged by and axially aligned with the annular support body. A part of the blade-bearing portion spaced from the hinge mechanism comprises a blade that protrudes radially inwards of the annular body, such that in use the urging of the two portions towards the closed position urges the pipe against the blade so that rotation of the cutting device around the pipe cuts the pipe.

Abstract: Disclosed herein is a method for the secure deletion of data stored within a data processing system. The method includes the steps of executing a flag routine, wherein data is flagged for possible future deletion; executing an authorization routine to authorize the deletion of the flagged data; and receiving a deletion trigger, the deletion trigger initiating the execution of a data deletion routine to delete the flagged data. An exemplary data processing system configured to delete the flagged data is also provided.