Verification of Encrypted Data Without Access to Plaintext

A first computing system comprising one or more processors and one or more non-transitory computer-readable media storing instructions that are executable by one or more processors to cause the first computing system to perform operations, the operations comprising:

• receiving, from a second computing system comprising one or more second computing devices, first cryptographic data indicative of at least one file modification;
• receiving, from a third computing system comprising one or more third computing devices, second cryptographic data indicative of the at least one file modification;
• and
• providing, to the third computing system based on the first cryptographic data and second cryptographic data, verification data indicative of a correctness of metadata associated with the at least one file modification.

One or more non-transitory computer-readable media storing instructions that are executable by one or more processors to cause a computing system to perform operations, the operations comprising:

• obtaining one or more encrypted files;
• decrypting the one or more encrypted files to obtain one or more unencrypted working files, wherein the one or more unencrypted working files comprise first data indicative of one or more prior modifications to the one or more unencrypted working files;
• cryptographically transforming second data comprising all or part of the first data to generate a cryptographically transformed value;
• providing, to a computing system comprising one or more computing devices, the cryptographically transformed value and metadata associated with the one or more prior modifications;
• and
• receiving, from the computing system, verification data indicative of an authenticity of the metadata.