In the Telegram API it is stated that Telegram support Perfect Forward Secrecy in their “secret chats”. It is also stated that
official Telegram clients will initiate re-keying once a key has been used to decrypt and encrypt more than 100 messages, or has been in use for more than one week, provided the key has been used to encrypt at least one message.
So my question is, in this case, if a session key gets compromised, is it possible for an attacker to read 100 messages (or possibly more)? If yes, can we still say that perfect forward secrecy is satisfied here?