Abstract: Techniques for ensuring privacy of users are provided. In one approach, a Web server receives a request from a Web browser. The Web browser generates an encryption key and sends the encryption key to the Web browser in a cookie. The Web server later encrypts the request (or any portion thereof) using the encryption key and deletes the encryption key so that the Web server is unable to determine the actual contents of the encrypted data. If the user does not delete the cookie (which would delete the encryption key), then a later request from the Web browser includes the cookie and the encryption key. The Web server is then able to decrypt the previously encrypted data and perform substantive analysis on the decrypted data.

Abstract: A system is disclosed for measuring click traffic quality by scoring clicks made on sponsored advertisements. A click score generated by the disclosed system may enable advertisers and publishers to distinguish between legitimate and fraudulent clicks. The disclosed system may filter click data associated with a click made on a sponsored advertisement. The system may generate a click score that may represent the confidence with which the quality of a click may be determined. The system also may generate a confidence interval associated with the click score.

Abstract: Techniques for ensuring privacy of users are provided. In one approach, a Web server receives a request from a Web browser. The Web browser generates an encryption key and sends the encryption key to the Web browser in a cookie. The Web server later encrypts the request (or any portion thereof) using the encryption key and deletes the encryption key so that the Web server is unable to determine the actual contents of the encrypted data. If the user does not delete the cookie (which would delete the encryption key), then a later request from the Web browser includes the cookie and the encryption key. The Web server is then able to decrypt the previously encrypted data and perform substantive analysis on the decrypted data.

Abstract: A system and method distributes keys from a central node to branch nodes in a tree network. The central node and the branch nodes within the tree network are initialized. A root public/private key pair is generated by the central node. Each branch node is loaded with the root public key and a unique branch public/private key pair. A generated group key is distributed to the associated branch nodes. New branch nodes are given the group key after they are associated with the network. Re-keying of the group key throughout the system is done via the central node either at the expiration of the group key, when a node is not sure if a group key is still valid, or when the group key has been compromised.

Abstract: In the process for electrowinning of zinc from acid zinc sulfate electrolyte, electrolyte is recirculated to the cells and a portion of the electrolyte is returned to the leaching operation of zinc-bearing material. By only returning electrolyte that overflows from electrolytic cells that contain new and/or recently cleaned anodes to the leaching operation, the amount of sludge in the cells can be reduced, the period between cleanings of cells can be lengthened and the amount of addition agent for controlling the lead content of deposited zinc can be reduced. Electrolyte overflowing from only those cells that contain new and/or recently cleaned anodes is diverted and kept separate from recirculating electrolyte from all other cells by providing separate means for collecting and transferring electrolyte to the leaching operation.