A file with .spc extension is a digital security certificate file created in the PKCS # 7 format. Several applications, create these certificate files for secure exchange of information. Few such applications include OpenSSL and the Signcode.exe application included with Microsoft’s .NET Framework. Like other certificate files such as .cer, .p7c, and .ssp, the SPC files contain the public key information that is encrypted with a private key. This public key can be shared with users publicly while the private key is kept confidential.
SPC File Format - More Information
The SPC files are saved to disc as binary files that can be opened in any text editor but are not human readable. These are based on latest version of PKCS # 7 which is available RFC 2315.