At 05:30 AM 5/31/02 -0700, surinder pal singh makkar wrote: >Hi List, > >I am a newbie in cryptography. What I have learnt till >now is that in assymeric cryptography scenario we have >a private key and we generate the public key >corresponding to it and then we send it to the central >agency.
Correcting: You generate a key-pair, then you decide which half to keep secret. You publish the other half, where publish means gives to known associates. Or if you like encrypted spam, you publish to a well-known repository. You may repeat this and use different key-pairs with different groups of correspondents. >Suppose after sometime I have a private key and the >public key. Is there some software tool which can tell >me whether the public key is the same corresponding to >the private key I am having. Yes: encrypt a message using KeyA and decrypt with KeyB. If it decrypts, they are matching. Or you are extraordinarily unlucky :-) Generally the wrong key will decrypt to noise. Also is there some tool >which can tell me whether the keys have been curropted >or not Tools might include self-integrity info (CRCs, hashes, etc.) in their file formats; YMMV. If any bits in either half of the key data are changed, you lose.