Τι είναι το THEMIS; The World Wide Web begins to look like the Wild West. Lately, we've learned that a great deal of Internet traffic is being watched by various agencies. Systems like Tor Project allow users to publish and share anonymously.
Τα συστήματα ανωνυμίας στο Internet such as Tor or simple proxies provide enormous public benefits, helping journalists, activists and others to communicate privately, away from the prying eyes of the "big guys" of the Internet.
What is Tor?
These systems, however, have been downgraded by criminals who use them to support their illegal activities. Tor has allegedly been used to help sell illicit drugs and spread child pornography, among others. With complete anonymity, criminals are often free to do what they want with little or no impact.
Researchers from Iowa State University try to solve this problem with an approach that they call accountable anonymity. Yong Guan, an associate professor of electrical and computer engineering and his students, has devised a system that offers anonymity to honest users, but he charges responsibility to someone who will use it for illegal operations.
"The lack of accountability in these anonymous services is easy to exploit," says Guan. "Criminals use anonymous systems like Tor to commit crimes against innocent people online and in the real world. I thought there was no real need for accountability under these systems to protect honest Christians who simply wish to exchange legitimate information anonymously. ”
The Tor works by sending information through a series of nodes and using multiple encryption levels at each stop. When the information reaches its destination, the encrypted messages are unlocked with a key and the original message becomes readable. Tor encryption layers disguise the origin of the message, thus providing anonymity, but with a high computer cost. Messages circling from one network to another, get from one encryption layer with each bounce, which takes time and computational power.
Guan's system, which he named THEMIS (THEMIS) is designed to minimize the computational power used to send messages and provides a way to track the source of the message, which is by definition considered malicious. From its own design, the system avoids spending computational power to send illegal and harmful messages.
"With a level of accountability, criminal online activity will be reduced," says Guan. By measuring the computing power spent, support for criminal activities will be reduced. That's a good thing. "
The new system aims to offer four features:
First and foremost, the system must provide anonymity under normal conditions. Users who wish to exchange information legally without being monitored will be able to do so without problems.
"Providing reliable anonymity is the first," Guan says. "Without it, users will not use the system."
Second, the system should, under certain conditions, allow the identification of sources, without hindering the anonymity of other users. This involves a number of steps, including noticeς των αρχών επιβολής του νόμου. Αυτό το χαρακτηριστικό θα μπορούσε να χρησιμοποιηθεί για να βρουν τους αποστολείς των κακόβουλων μηνυμάτων, και απαιτεί τη συνεργασία της βασικής γεννήτριας του συστήματος και της baseς data της υπηρεσίας μητρώου της εταιρείας παροχής Internet.
"Our system provides law enforcement with the means to catch criminals who want to distribute illegal or harmful messages," says Guan. "Without any kind of responsibility, users tend to show a lack of self-control."
Third, the system must be a compatible incentive. This means that users must have an incentive to use the system as intended for use. Without a compatibility incentive, users can bypass simple system features if they do not want to comply with them.
Fourth, none of the system will be able to shape or appropriate an honest user. THEMIS manages this by using digital signatures that are impractical to produce without the keys from the source.
"Creating keys is computationally difficult," says Guan. "If a node wants to get the signature key, or sign a message without the source signature key, it has to solve a problem that is incredibly difficult, even for the fastest computers."
The THEMIS system consists of two separate re-encryption proxy systems. One is a multi-hop proxy re-encryption system and provides an anonymous communication channel between the source of the message and its destination. It is very similar to Tor, since THEMIS messages are "returned" through various proxies. However, instead of adding layers of encryption, THEMIS encrypts the original message at each stop with XAG encryption. Thus each proxy along the path knows only its predecessor and successor, and proxies re-encryption keys of the corresponding channels are hidden in the message in an onion header. The onion header layers contain the information about the corresponding node.
The rationale also provides for the attribution of responsibility for malicious messages. As with any other encryption system, public keys and private keys are used to ensure that messages arrive where they need and are readable only by the recipient. However, the new AFGH encryption key included in each message also serves as billing information linking the destination of the message to its source. Without the AFGH re-encryption key, the messages are unreadable.
At the request of the recipient of the message, law enforcement authorities may use the AFGH to identify the source of the message.
"If someone does not report the message as malicious," Guan said, law enforcement may not be involved.
Guan envisions his system as a way that law enforcement can identify the senders of malicious emails and those who are leaking important documents. THEMIS is the first system to provide both anonymity and debit and the first anonymous network that uses re-encryption using toy multi-hop proxy. No relationship with Tor.
"The next step," says Guan, "is to try it on a large scale over the Internet." That way, we can really see how well it performs. "
Article is a translated republication of Creating Accountable Anonymity Online: Systems That Currently Allowed Users Complete Anonymity Are Being Abused by Science Daily
