Select ALL statements that correctly describe the cipher types in this material.

### Why this is right - **A** is true: substitution changes symbols by replacing them according to a rule. - **B** is true: transposition changes the order or positions of symbols. - **C** is true: polyalphabetic substitution draws on more than one alphabet. ### The concept These terms describe ways a cipher transforms symbols. Substitution changes symbol identity, while transposition keeps the symbols but rearranges their positions. Public and private key pairs describe asymmetric cryptography, not a type of transposition. ### The other options - **D. A transposition cipher is defined by using a public and private key pair**: a key pair is associated with asymmetric cryptography. A transposition cipher is defined by rearranging data. ### Terms - **Polyalphabetic**: using multiple substitution alphabets. - **Asymmetric cryptography**: a method based on a public and private key pair. ### Remember Ask whether symbols are replaced or repositioned to distinguish substitution from transposition.