On 24 November 2025 Tor announces adoption of Counter Galois Onion (CGO) for relay encryption, with implementations underway in Arti (Rust) and C Tor to protect circuit traffic from tagging attacks, add forward secrecy, and modernize authenticators; development work includes refactoring relay cell handling and experimental enablement in Arti.

CGO uses a Rugged Pseudorandom Permutation (RPRP) called UIV+ to provide wide-block encryption, chaining tags and nonces for tamper resistance, and replaces the 4-byte digest with a 16-byte authenticator—key changes intended to prevent internal covert-channel tagging, provide immediate forward secrecy, and reduce malleability; next steps are enabling CGO by default in Arti, negotiating CGO for onion services (Arti-only likely), and performance tuning for modern CPUs.

Read More: Stack Duo Gains Tor Support for Monero and Bitcoin

• What is Counter Galois Onion and when was it announced for Tor? CGO is a new relay encryption algorithm announced 24 November 2025.
• Which Tor implementations will support CGO and in which jurisdictions? Arti (Rust) and C Tor will support CGO, applicable globally where Tor software is used.
• How does CGO improve security for Tor users in local networks? CGO prevents tagging attacks, adds forward secrecy, and lengthens authenticators for stronger local-network protection.
• When will Arti enable CGO by default and what are next deployment steps? Arti plans to enable CGO by default after experimental testing, then implement onion-service negotiation and CPU performance tuning.

免责声明：本文章仅代表作者个人观点，不代表本平台的立场和观点。本文章仅供信息分享，不构成对任何人的任何投资建议。用户与作者之间的任何争议，与本平台无关。如网页中刊载的文章或图片涉及侵权，请提供相关的权利证明和身份证明发送邮件到support@aicoin.com，本平台相关工作人员将会进行核查。