Which algorithm used in modern data encryption is designed for high performance in software implementations?

ChaCha is specifically designed to offer high performance in software environments, making it particularly suitable for devices where hardware acceleration for encryption might not be available. This algorithm is built to be efficient and fast, while still maintaining a strong security posture against various forms of cryptographic attacks.

ChaCha's construction allows it to perform well on various computing architectures, especially those without specialized hardware for encryption, unlike some other algorithms that might rely on hardware optimization to achieve better performance. This characteristic makes it a popular choice for mobile devices and applications where resource constraints and performance are critical.

In contrast, while AES is widely regarded as a secure and efficient encryption standard, it can be slower in pure software implementations compared to ChaCha. GCM mode is a mode of operation for block ciphers rather than a standalone encryption algorithm; its performance depends heavily on the underlying block cipher, which in many cases is AES. 3DES, while historically significant, is now considered outdated and less efficient compared to modern standards like ChaCha and AES.