First of all, we have used a secure algorithm to allow safe key exchanges between a sender and a recipient. Letter Sealing uses the Diffie-Hellman (DH) method of key exchange instead of the RSA method. With this method, each user has a public key and a private key. Each user holds on to their private keys and only exchange the public keys with other users. When two public keys are exchanged, obfuscated data is created between the two users. This prevents any third party from intercepting the messages..
When the values are exchanged, users are able to exchange shared secret data without the risk of exposure. While the RSA method also had a similar system, it was replaced with the DH method because it was more efficient than storing each individual RSA key on user devices.