Margarita Zimmermann [SEP] voice type
Margarita Zimmermann
Margarita Zimmermann (born October 3, 1942) is an Argentine mezzo-soprano, particularly associated with the Italian and French repertories.
Life and career.
Born in Hurlingham, Buenos Aires Province, Argentina, she made her debut as a recitalist at the Teatro Colón of her native city. She then left for Europe, where she studied notably with Gérard Souzay. 
She made her European debut at La Monnaie in Brussels, as Cherubino in "Le nozze di Figaro", in 1977. During
PGPfone
PGPfone was a secure voice telephony system developed by Philip Zimmermann in 1995. The PGPfone protocol had little in common with Zimmermann's popular PGP email encryption package, except for the use of the name. It used ephemeral Diffie-Hellman protocol to establish a session key, which was then used to encrypt the stream of voice packets. The two parties compared a short authentication string to detect a Man-in-the-middle attack, which is the most common method of wiretapping secure phones of this type. PGPfone