Blackberry Corporation

Isara Corporation

Marek Paruzel

Kristof Takacs

Jameson Bauer Hyde

Michael Kenneth Brown

Ravi Singh

Atsushi Yamada

Anthony Chun Li Hu

In some aspects, nodes of a cryptographic hash tree are stored in a buffer memory. Nodes of an active subtree are stored in a first set of indexed locations in the buffer memory, and nodes of a future subtree are stored in a second set of indexed locations in the buffer memory. A one-time signature (OTS) is generated based on a signing key associated with a current value of a signing index. An authentication path for the OTS is generated by retrieving a subset of the nodes from the buffer memory. A new node of the future subtree is calculated based on the current value of the signing index and stored in the buffer memory. The signing index is then advanced from the current value to a next value of the signing index.

Managing nodes of a cryptographic hash tree in a hash-based digital signature scheme

A system and method to monitor executing processes are disclosed. A respective starting fingerprint of memory of each executing process within at least one process is determined during a system startup phase that is prior to a device operational phase. A present fingerprint of memory of the selected executing process within the at least one process is determined during the device operational phase and while a selected executing process is executing. A difference between the respective starting fingerprint of the selected executing process and the present fingerprint of the selected executing process is determined and an indication of the difference for the selected executing process is reported based on determining the difference.

Executing process code integrity verificaton

In a general aspect, a Merkel signature scheme (MSS) uses subtree data. In some aspects, subtree data is loaded from a non-volatile memory into a volatile memory. The subtree data represents one or more nodes of a subtree of a cryptographic hash tree and a first authentication path portion that includes nodes outside the subtree. The subtree includes a subtree root node at a level below a root node of the cryptographic hash tree and lowest-level nodes of the cryptographic hash tree, which are based on respective verification keys for a one-time signature (OTS) scheme. An OTS is generated using a first signing key associated with a first verification key, which is associated with a lowest-level node in the subtree. The OTS, the first verification key, the first authentication path portion, and a second authentication path portion comprising one or more nodes of the subtree are sent to a recipient.

Merkle signature scheme using subtrees

A system and method to control establishing inter-process communications are disclosed. A message from a requesting process that is different from a serving process is received at the serving process via an inter-process communications facility. A current fingerprint of memory associated with the requesting process is determined. Whether a previously determined fingerprint is stored for the requesting process is determined where the previously determined fingerprint was determined since initialization of a processor executing the serving process. Based on a determination that the previously determined fingerprint is not stored, the current fingerprint is stored and a communications channel is established between the serving process and the requesting process. Based on a determination that the previously determined fingerprint is stored and that the previously determined fingerprint matches the current fingerprint, the communications channel is established between the serving process and the requesting process.

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Kitchener, Canada

Marek Paruzel