That is not a typo. "This" refers to the mode of operation (CTR with nonce derived from HMAC) and it's possible to prove that this mode is secure under deterministic CPA, in marked contrast to other deterministic encryption modes (such as ECB or CBC with a fixed IV). I've clarified what "this" refers to in 6d6e96f82b63cc09274367668de90d62dc027a32.
That is not a typo. "This" refers to the mode of operation (CTR with nonce derived from HMAC) and it's possible to prove that this mode is secure under deterministic CPA, in marked contrast to other deterministic encryption modes (such as ECB or CBC with a fixed IV). I've clarified what "this" refers to in 6d6e96f82b63cc09274367668de90d62dc027a32.