<p>I have done BSc in Electrical Engineering and have done research in network security and have 7 papers. I have taught Cryptography to undergrad students.</p>
<p>I am interested in theoretical Cryptography and wants to do PhD in this area.</p>
<p>Do I really need to have strong background in computer science theory to purse PhD in Cryptography or admission committee will see my good research potential?</p>
<p>Go to the program web sites to see their preparation requirements.</p>
<p>Sounds like you have quite a strong background. </p>
<p>Don’t people enter that field from a number of different backgrounds, not just computer science?</p>
<p>As the previous poster suggested, check the websites of programs that interest you. Also, email professors with whom you want to work at those programs and ask them directly.</p>
<p>Just apply and see what happens. There’s no sense in obsessing <em>during</em> the application season, especially on things you can no longer change.</p>