The Internet Security Research Group (ISRG) is a public-benefit non-profit corporation based in California which focuses on Internet security.

[2] The group is known for hosting and running the Let's Encrypt service, which aims to make Transport Layer Security (TLS) certificates available for free in an automated fashion.

[3] Josh Aas serves as the group's executive director.

[4] ISRG has three project areas: The Internet Security Research Group has 10 board members as of June 2024[update].

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