Abstract: Tamper-evident electric paper is made of two sheets of electric paper bonded together, the bottom sheet of which includes a pattern. Any attempt to erase a writing on the top sheet of electric paper results in the pattern on the bottom sheet of electric paper being erased. Therefore any tampering by erasure of a writing on the tamper-evident electric paper is revealed by the absence of a portion of the pattern on the bottom sheet of electric paper. Single sheet tamper-evident electric paper has a complex pattern, such as an encryption, printed on a single sheet of electric paper. Any attempt to erase a writing on the electric paper also erases a portion of the encryption, thereby providing evidence of tampering.

Abstract: Selected regions of an electronically modifiable display are fixed while other regions are left electronically modifiable. The selected regions are fixed by various methods including subjecting the selected regions to heat, light or pressure. In some embodiments, the fixed regions are reversibly fixed so that changes can be made to the fixed regions.

Abstract: Tamper-evident electric paper is made of two sheets of electric paper bonded together, the bottom sheet of which includes a pattern. Any attempt to erase a writing on the top sheet of electric paper results in the pattern on the bottom sheet of electric paper being erased. Therefore any tampering by erasure of a writing on the tamper-evident electric paper is revealed by the absence of a portion of the pattern on the bottom sheet of electric paper. Single sheet tamper-evident electric paper has a complex pattern, such as an encryption, printed on a single sheet of electric paper. Any attempt to erase a writing on the electric paper also erases a portion of the encryption, thereby providing evidence of tampering.

Abstract: A system for the capture and playback of temporal data representing a collaborative activity such as a meeting. Such temporal data is captured by one or more capture devices (e.g. audio recordings or an electronic whiteboard). Temporal data is comprised of timestreams and events. Timestreams are sets of timestamped data which represent some recordable aspect of the meeting. Events are contained within a timestream that represent natural activities that occurred during the course of the session. Events are used to create indices which provide direct access to a point or span in time during the collaborative activity. Playback of a session is performed under the control of a session access device. Coupled to the session access device are a plurality of players for playing back timestreams. The session access device utilizes event information to create a user interface for controlling session replay. The user interface is comprised of a plurality of windows.