Abstract by anuja a sonalker on Asymmetric Key Distribution

3.10.2 Key Distribution Problem 
In the case of the Trusted Dealer, there exists a key distribution problem. A safe 
transmission of the initial private key shares is indispensable to the proper functioning of 
the algorithm. For the safe transmission of the initial shares, which the trusted dealer 
deals to all the share servers in the party, any crypto scheme can be applied. We propose 
one solution: each share server has its own encryption-decryption method with its own 
individual public and private key pairs. While its private key (used for decryption) is 
known only to itself, its public key is registered in a public file system with the trusted 
dealer. This file system is totally public in nature and the revelation of this information 
does not pose any threat to this scheme.
When the trusted Dealer has completely computed all the shares it needs to distribute 
them to each share server. The TD encrypts each message using the corresponding share 
servers public key, Ex, and sends it out via an insecure means of communication. The 

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share server on receipt of this message, M
x
, uses its private key D
x
to decrypt the 
message, which contains its new keys. 
For example, if the TD desires to send share server S1 his set of private keys in a 
message M
s1
, it would look into his public file and compute the following cipher text C
s1
and send it over to S1. S1 would then compute M
s1
using D
s1 
and retrieve its new set of 
shares. Further, all the communication channels are assumed to be created over SSL for 
added security. 
3.10.3 Physical Break-ins and Compromising the Trusted Dealer 
The algorithm is believed to be computationally secure. Physical break-ins are not an 
immediate issue for the algorithm and it is assumed that physical security is being 
handled exceptionally well by the designated authorities and there is no chance for the 
keys to be physically leaked out of the system under consideration even by the owner. 
The Trusted Dealer is a single point of failure and so, a prime target for attack, as it is the 
sole entity in the system to possess complete knowledge of the complete private-key and 
the shares.
The Trusted Dealer is secured from any takeover thus. As far as physical break-ins are 
concerned, as a continuation of our initial physical security assumption, we tend to 
believe that the environment of key generation is physically isolated from other entities. 
The possibility of the keys being physically robbed or leaked out of this environment is 
nil due to the security agencies at work and the fact that the trusted dealer is a temporary 
agent created for the sole purpose of key share generation and distribution. It then self-
destructs once its assigned tasks are completed. The TD does not save the key shares on 
to any media or prints them for any recording purpose. Once the Trusted Dealer self-
destructs, there is no place where all the private shares of all the share servers can be 
found together. 

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