Derived unique key per transaction

Abstract: Secure media broadcast over the Internet poses unique security challenges. One problem is access control to a large number of subscribers in a public broadcast. A common solution is to encrypt the broadcast data and to disclose the decryption key to legitimate receivers only. However, how do we securely and efficiently establish a shared secret among the legitimate receivers? And most importantly, how can we efficiently update the group key securely if receivers join or leave? How can we provide reliability for key update messages in a way that scales up to large groups? Recent research makes substantial progress to address these challenges. Current schemes feature efficient key update mechanisms assuming that the key updates are communicated reliably to the receivers. In practice, however the principal impediment to achieve a scalable system is to distribute the key updates reliably to all receivers. We have designed and implemented ELK, a novel key distribution protocol, to address these challenges with the following features: ELK features perfectly reliable, super-efficient member joins; ELK uses smaller key update messages than previous protocols; ELK features a mechanism that allows short hint messages to be used for key recovery allowing a tradeoff of communication overhead with member computation; ELK proposes to append a small amount of key update information to data packets, such that the majority of receivers can recover from lost key update messages; and ELK allows to trade off security with communication overhead.

Abstract: A method is provided for protecting distributed software which relies on a unique factor such as an accessible serial number or the generation of a profile or fingerprint of the computer of the user which is entered individually and/or with a random factor to generate a unique first key which will differ for different computers. The first key is sent to a processing center which then generates a second key. The user applies the second key which compares the unique and/or random factors. If the comparison matches, the first and second keys are used in an algorithm in the software to generate a decrypting key permitting the customer to purchase the selected program(s).

Abstract: Improved key management is provided by a public key replacement apparatus and method for operating over insecure networks. An active public key and the mask of a replacement public key are provided by a key server to nodes where the active key is used to encrypt and verify messages. To replace the active public key with the replacement public key, a key replacement message is sent to the node. The key replacement message contains the replacement public key and contains the mask of the next replacement key. The mask of the replacement public key may be generated by hashing or encrypting. The key replacement message is signed by the active public key and the replacement public key. Nodes are implemented by a computer, a smart card, a stored data card in combination with a publicly accessible node machine, or other apparatus for sending and/or receiving messages. In a particular application, a financial transaction network, nodes are consumer nodes, merchant nodes, or both, and transactions are securely sent over a possible insecure network.

Abstract: n recent years, public key infrastructure (PKI) has emerged as co‐existent with the increasing demand for digital security. A digital signature is created using existing public key cryptography technology. This technology will permit commercial transactions to be carried out across insecure networks without fear of tampering or forgery. The relative strength of digital signatures relies on the access control over the individual’s private key. The private key storage, which is usually password‐protected, has long been a weak link in the security chain. In this paper, we describe a novel and feasible system – BioPKI cryptosystem – that dynamically generates private keys from users’ on‐line handwritten signatures. The BioPKI cryptosystem eliminates the need of private key storage. The system is secure, reliable, convenient and non‐invasive. In addition, it ensures non‐repudiation to be addressed on the maker of the transaction instead of the computer where the transaction occurs.