A way to muzzle the controversial Carnivore snooping system has been developed by graduate researchers at Dartmouth College in the US.

Although it doesn't take all the bite out of Carnivore, the students' system goes some way to eliminating the abuse potential of the data snooper.

In their proposal, 'Prototyping an Armoured Data Vault', Alex Iliev and Sean Smith outline a digital rights management system geared towards removing the human element when accessing Carnivore-captured data.

One of the main concerns of Carnivore is that because it captures all data passing through an ISP, investigating authorities have access to more data than they have a legal right to analyse.

Iliev and Smith's data vault limits access to Carnivore data by "storing packets securely, so that they may be accessed only through the security mechanism imposed by the vault."

All data captured by Carnivore would be encrypted and the only decryption key would be kept by the secure digital vault. Any authority seeking to analyse the data would need a court-granted digital signature, which would be recognised by the vault. The vault would then only give up the data as specified by the court, leaving no chance for the investigating body to access other data.

Security is further enhanced by the fact that the cryptographic brain behind the vault is an IBM 4758 cryptographic co-processor, which is designed to destroy itself and all encrypted data if it detects physical penetration, power sequencing, temperature and radiation attacks against itself.

Iliev and Smith have said that their design is not an encouragement for authorities to start capturing data here, there and everywhere, but instead as an assurance that if data is captured it is done so securely and responsibly.

A White Paper on the Armoured Data Vault is available here.