"Secret Key" is the Pitera line...

"Secret Key" is the Pitera line

http://news.pg.com/blog/birth-icon-sk-ii

Trademark was first filed in 1996, with renewals every decade (2006, 2016);

https://www.trademarkia.com/ctm/secret-key-000269407.htm

"As scientists were searching for a key ingredient for a new skin care line, they chanced upon a Japanese brewery where they noticed the brewery's elderly workers, who were in constant contact with the yeast fermentation process, and had yet really soft, smooth hands.

After years of researching with a total of 350 different strains of yeast, they discovered that there was indeed one yeast that was rich with nutrients benefiting the skin - named pitera. It was then acquired by the Japanese branch of Max Factor & Company (named after a Polish-Jewish cosmetician). They thus launched its first cosmetics product - Max Factor Secret Key with Pitera in December 1980. The brand was later renamed as SK-II when it was brought over by Procter & Gamble. "