Analysis of various methods

1. Creation of Message Digest using DSA and RSA algorithms and running the program on data of various size.

Table 1.

Estimation of time n milliseconds taken to generate messase digest as a function of message size and algorithm.
           <--------Message Size-------------->
Algorithm  0 KB		1KB	2KB   	3KB   	4KB

SHA-1       28		31	31	31	31      
MD5         26          29      41      41      41

As shown in Table 1 it is seen that both the methods use more or less same time for creating a message digest.
also the time taken to generate message digest is almost same for various file sizes for both the algorithms.

2. Signature generation using DSA and RSAon for data files of various size.

Table 2
Estimation of time in milliseconds taken for signature generation as a function of message size, key size & algorithm

		<----Message Size------>
Algorithm     0KB 	1kB 	2KB 	3KB 	4KB
DSA          319        345      317    325     331
RSA	    1625       2245     1386   1368    1058

As shown in table 2 above it is seen that DSA algorithm takes very less time (3to4 times) then the corresponding time for RSA algorithm to generate signature.
Also there are less variations in signature time generation for DSA for various sizes of data as compared to RSA.

3. Signature verification using DSA and RSA as a function of message size, key size & algorithm

Table 3

Estimation of time inmilliseconds taken for sigature verification as a function of message size, key size & algorithm

		<-------------Message Size------------>
Algorithm      0KB    1KB  2KB   3KB    4KB
DSA            36     37    36    39     35
RSA             6     21     7     7      7


It is seen that RSA takes very less(alost 5 times) time to verify the signature compared to DSA. The time taken to verify signature is almost constant irrespective of the size of data for both the algorithms.






