Since OTP have to be agreed upon in advance, they may be longer than the plaintext. So in this case, how is the encryption done? Is the OTP truncated to the same length of the plaintext before encrypting or is some kind of padding used - how does it work?
I am talking about the case where Alice & Bob exchange a book of One Time Pads. Each page of the Pad is used for one plaintext encryption. So each page is of a fixed length & is always longer than the plaintext which it encrypts. So how is the difference in length handled?
As per Dan Boneh's book, a scheme which leaks the length of the plaintext cannot satisfy the definition of perfect security. If we only use that much part of the OTP same as the length of the plaintext, then we are essentially leaking the length of the plaintext because then ciphertext is same length of the plaintext. So how is this handled? I am looking for an authoritative source on how this is handled? Is it via padding? If so, how is the padding done?