Friday, May 18, 2007
Friday, May 4, 2007
Ring signature is a "signer-ambiguous" signature, the verifier can only ensure the message is signed by 1 out of n purported users, but not exactly whom. For signing, (i.e. to produce a ring signature), the actual signer declares an arbitrary set of possible signers that
must include himself, and computes the signature entirely by himself using only
his secret key and the others' public keys. In particular, the other possible "members of this group"may be completely unaware that their public keys are used by a
stranger to produce such a ring signature on a message they have never seen and
would not wish to sign.
You may assume additional properties that you find useful, e.g. 1. perfect anonymity, 2. there exists a guy who can revoke the anonymity of the signature; or 3. we can tell if two signatures are signed by the same signer, but with the identity remains hidden. You name it, I (try to) build it!
Title: A generic anti-spyware solution by access control list at kernel level
Spyware refers to programs that steal the user information stored in the user's computer and transmit this information via the internet to a designated home server without the user being aware of this transmission. Existing anti-spyware solutions are not generic and flexible. These solutions either check for the existence of known spyware or try to block the transmission of the private information at the packet level. In this paper, we propose a more generic and flexible anti-spyware solution by utilizing an access control ist in kernel mode of the operating system. The major difference between our approach and the existing approaches is that instead of asking a guard to look for the theft (spyware) or control the exit of the computer (and hence giving the spyware enough time to hide the information to be transmitted). we put a guard besides the treasure (the private information) and carefully control the access to it in the kernel mode. We also show the details of an implementation that realizes our proposed solution.
Monday, April 30, 2007
Ethical Hacking services - the positive side of hacking are sold under the modern name of "Network Security Services".
Ethical hackers help their customers to find and plug in the security loop holes in their respective sites. Watch out guys their is more to more...this is just an introduction
Step 1: a requestor r locates available resources sending a broadcast Query message to ask for the files it needs to download. Other peers will answer with a QueryHit message to the requesting node to notify that they have the requested resource.
Step 2: Upon receiving a set of QueryHit messages, r selects an offerer o and polls the community for any available reputation information on o sending a Poll message. As a result of step 2, r receives a set V of votes, some of which express a good opinion while others express a bad one.
step 3: r evaluates the votes to collapse any set of votes that may belong to a clique and explicitly selects a random set of votes for verifying their trustworthiness.
step 4: the set of reputations collected in step 3 is computed into an aggregated community-wide reputation value. Base on this reputation value, the requestor r can take a decision on whether accessing the resource offered by o or not.After accessing the resource r can update its local trust on o (depending on whether the downloaded resource was satisfactory of not).
P2PRep is a reputation-based protocol runs in a completely anonymous P2P networks. In P2PReP, local reputation management and community-wide reputation management are two different levels. Local reputation is defined as one single peer’s opinion of one other peer’s reputation, based on its formal experience. The community reputation means the aggregated general opinion given by multiple peers. P2PRep is generally combine these two factors togeter.
P2Prep works well in the environments of the percentage of malicious peers’ increasing and decreasing by changing well-behaved ones to rogues ones and changing rogue ones into well-behaved ones. As to the turn over case in peers’ population, P2PReP confirms its robust-ness showing a percentage of malicious downloads greater about 1% than scenario with no change.
Monday, April 2, 2007
Friday, March 23, 2007
An example is :
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.
Sorry, no mailbox here by that name. vpopmail (#5.1.1)
So, have other people also been getting such emails too ?
And what could these signify ?