In the book "Introduction to the Theory of Computation", Michael Sipser writes
The field of cryptography, as this area is known, now extends well beyond secret codes for private communication and addresses a broad range of issues concerning the security of information. For example, (1) to allow electronic elections whereby participants can vote over a network and the results can be publicly tallied without revealing any individual’s vote, while preventing multiple voting and other violations; and (2) to construct new kinds of secret codes that do not require the communicators to agree in advance on the encryption and decryption algorithms.
(Chapter: Advance Topics in Complexity Theory, section: Cryptography)
I am assuming that the example (1) refers to Blockchain technology. Are there any other ways of achieving the same?
For the example (2), I am not sure which technology is he trying to refer. Any idea?