The Special Intensive Revision (SIR) commenced in Bihar under Election Commission of India (ECI) order no. 23/2025-ERS (Vol. II), dated June 24, 2025. Phase II followed on October 27, 2025, across 12 states and Union territories with about 51 crore electors, and Phase III, ordered on May 14, 2026, extends the exercise to the rest of the country including Delhi except Himachal Pradesh, Jammu & Kashmir and Ladakh, covering 19 states and UTs, including 36.73 crore electors. In Association for Democratic Reforms v Election Commission of India, 2026, the Supreme Court upheld the commission’s power to conduct the exercise subject to the safeguards of notice, hearing, a reasoned order and appeal. According to the communication of the United Nations Special Rapporteurs dated May 1, 2026, about 5.2 crore (52 million) names were removed in Phase II alone.The ECI discontinued its documented de-duplication software during the Bihar SIR and deployed undocumented systems midway through Phase II. ERONET, originally built by C-DAC under the Ministry of Electronics and Information Technology (MeitY), has since 2023 been operated as ERONET 2.0 by Tata Consultancy Services, a fact the ECI never disclosed and the Reporters’ Collective established from shareholder filings. On December 29, 2025, the West Bengal chief electoral officer’s office admitted in writing that the flagging software was malfunctioning because the 2002 base data “had not been digitised accurately”.Every determination in the exercise rests on a digitised copy of a two-decade-old paper roll. The only official confirmation that computation forms part of the decision chain is a line in the commission’s presentation providing for “Computer Matching/Linking with Last SIR by ECINET”. The same presentation records that booth level officers may match electors against an “All-India database”. The remainder of this record has been reconstructed from orders, press notes, affidavits, investigative reporting and litigation.The systems deployedECINET, launched on January 22, 2026, consolidates about 40 legacy applications behind a single login, used by electors to file enumeration forms and search the digitised legacy rolls. The booth level officer-app is the field instrument through which booth level officers digitise forms, record mapping outcomes and receive centrally distributed lists of flagged electors.ERONET, the registration officers’ backend, was originally developed by C-DAC under the Ministry of Electronics and Information Technology; Reporters’ Collective has established that ERONET 2.0 has been operated since 2023 by TCS, an arrangement the ECI never disclosed by the ECI and located that is recorded only in the company’s shareholder disclosures, with officials describing a system that was “changing on the go” as the rules were revised mid-exercise.The remaining layers are known only through journalism and litigation. A mapping algorithm linked current electors to the digitised legacy rolls, and unlinked electors were classified as “unmapped” and required to produce documents. When only about 3% of West Bengal’s electorate was returned as unmapped, the software was applied to mapped electors to flag “logical discrepancies”, marking 1.31 crore persons in West Bengal (17.11%) and 2.35 crore in Madhya Pradesh (41.22%).A machine transliteration engine converted Bengali-script rolls into English before matching. The infrastructure also contains the Photo Similar Entry and Demographically Similar Entry duplicate-detection tools, and the matching software is reported to have been developed by C-DAC. For none of these systems has the commission published a contract, tender, model description, matching threshold, false-positive rate, algorithmic impact assessment or data protection impact assessment.The digitised base rollsAnnexure V of the Phase II instructions of October 27, 2025, fixes the reference year for every state. In 2002 for most and 2003 for Bihar, Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Jharkhand, Punjab and Uttarakhand, 2005 for the North-Eastern States, Assam and J&K, 2006 for Arunachal Pradesh, and, within Tamil Nadu, a dual baseline of 2002 for 197 constituencies and 2005 for 37. These rolls existed as paper volumes and scans in Bengali, Telugu, Kannada, Marathi and other scripts.For West Bengal, Reporters’ Collective reconstructed the pipeline: the paper 2002 rolls, mostly in Bangla, were digitised, machine-translated into English through untested algorithms, and then compared by further algorithms against electors’ filings; the digitisation across the 12 Phase II states was carried out in haste, without per-state tests of whether the records could be read and matched, which a senior ECI official confirmed likely caused voters to be misidentified as suspicious.No contract, conversion method or error rate for this digitisation has been published, and the commission’s portal hosts the legacy data under a disclaimer that it appears as received from the state chief electoral officers.The consequences are on the commission’s own record for instance, on December 27, 2025, the West Bengal CEO’s office suspended hearings for unmapped electors, stating that the 2002 rolls had been incompletely converted from PDF into CSV, producing linkage failures in the BLO App for electors whose linkage was valid in the hard copies authenticated by district election officers; auto-generated notices were to be withheld. On December 29, 2025, the same office admitted in a letter to state officials that the flagging software was malfunctioning because the base data “had not been digitised accurately”.The rules were then changed in writing and the software adjusted to reduce the suspect count. The earliest reconstructed West Bengal rules used a parent-child age band of 15 to 45 years with a gender-name check, while the version recorded by the Supreme Court in January 2026 flagged gaps under 15 or over 50 years.The withdrawal of the documented de-duplication softwareThe ECI possessed a documented de-duplication tool, built under the 2016 electoral roll purification programme and mandated in “campaign mode” by its Manual on Electoral Rolls of March 2023, which refers to the software in six paragraphs and remains in force. In October 2025, Reporters’ Collective established that this software was not run during the Bihar SIR. The final Bihar roll consequently contained 14.35 lakh suspect duplicate entries, including 3.4 lakh exact matches on name, relative’s name and age, and 1.32 crore electors recorded at shared addresses, up to 650 in a single household.On November 24, 2025, the ECI stated on affidavit before the Supreme Court that it had discarded the software after 2023 because “the strength and accuracy of the results were variable”. No audit or public notice of that abandonment exists. Within days, different and undocumented algorithms were activated across the 12 Phase II states, without the manual’s ground-verification protocol. The questions posed by former civil servant E.A.S. Sarma, on when the defect was found, on what evidence, and where the audit is, remain unanswered.The commission’s position on artificial intelligenceThe ECI’s roll-management material and a May 2024 NIC newsletter describe the Photo Similar Entry and Demographically Similar Entry tools as AI-enabled, and a January 2026 India International Institute of Democracy and Election Management (IIIDEM) publication records that ECINET generates these reports while cautioning officials against over reliance on automated outputs.In November 2025, the West Bengal CEO’s office announced the use of facial recognition software, telling PTI it was “using AI due to an increase in complaints”. On January 12, 2026, the then West Bengal chief minister wrote to the Chief Election Commissioner (CEC) alleging that the 2002 rolls had been digitised using AI tools, introducing serious errors into electors’ particulars and producing wrongful logical-discrepancy categorisation. On July 12, 2026, in response to the UN Special Rapporteurs, an ECI official stated that “no artificial intelligence is used at any stage”, and the commission rejected the concerns as without basis.On September 20, 2026, the Delhi CEO’s office stated that “system-generated” notices were being issued to electors to correct their data in ECINET, while maintaining that no crisis existed. The label is, in law, secondary and whether the systems are rules-based or employ machine learning, the legal questions are whether classifications carrying the consequence of scrutiny and potential deletion rest on an intelligible differentia bearing a rational nexus to eligibility, as Article 14 requires, and whether the resulting notices satisfy the requirements of a reasoned show-cause notice.Informal instructions and the absence of operating proceduresThe Trinamool Congress placed on record before the Supreme Court that ground-level SIR instructions in West Bengal were issued through “informal and extra-statutory channels”. The Reporters’ Collective verified that the state’s chief electoral officer transmitted orders over WhatsApp, some contradicting written instructions, and district officials described features, protocols and flagged-elector lists arriving on the BLO App almost daily, without standard operating procedures.The commission assured the court that every notice reflected an officer’s application of mind; booth level officers stated to reporters that notices issued for every flag, including single-syllable spelling variations.Objections from within the commissionThe objections have also come from the commission. The Indian Express has reported that election commissioner Sukhbir Singh Sandhu and Vivek Joshi recorded at least 14 written objections between October 2025 and August 2026 to decisions taken without the commission’s approval.Several concerns the systems described above. Sandhu recorded that he learnt of a new IT module from the media. Joshi warned of the “gradual centralisation of the electoral roll database” and sought an audit of who could alter it. Sandhu also recorded that the Director General of the IT had no legal authority to restrict Electoral Registration Officers’ (EROs) access to ERONET.Moreover, in Goa, EROs found 97 flagged electors eligible after hearing directed by the Supreme Court, but the software could not record the decision, and the 97 were left off the final roll.Judicial consideration of the algorithmic processThe judgment of May 27, 2026, does not contain the words “software”, “algorithm”, “de-duplication”, “ECINET” or “technology” and the application for machine-readable rolls was treated as raising privacy concerns, with reference to Kamal Nath v Election Commission of India (2019) on the format in which rolls must be furnished, and closed without adjudication; Anmol Jain has analysed the institutional gaps this left.The Delhi proceedings have altered that position and on a writ petition by Anjali Bhardwaj and Amrita Johri, represented by Prashant Bhushan and Neha Rathi, a bench of Chief Justice Surya Kant and Justices Bagchi and Mohana heard the matter on September 22, 2026. Justice Bagchi observed: “Almost mechanically notices are being issued. In all probability, they are machine-generated notices”.The court directed the commission to define “logical discrepancy”, to indicate which documents can cure each category of discrepancy, to permit responses by WhatsApp or email without insistence on physical appearance, to apply the Bihar and West Bengal interim directions to Delhi, and to file a status report; the matter is listed after two weeks. These directions restate settled administrative law: a show-cause notice must disclose the grounds and material against the noticee with sufficient particularity to enable a meaningful reply (Gorkha Security Services v Government (NCT of Delhi) (2014)).The litigation has placed on record what the commission never published. In Delhi, electors are flagged where a parent appears fewer than 15 years older, a grandparent fewer than 40 years older, five or more siblings are recorded or the sibling age gap is under nine months; West Bengal’s official criteria flagged parent-name mismatches and parental gaps under 15 or over 50 years, with 24.21 lakh electors flagged for more than six recorded children. The rule set varies by state, unversioned and unaudited.Its Phase III output is now reported at about 1.76 crore logical-discrepancy notices across Telangana, Karnataka, Maharashtra and Delhi, per a Hindustan Times report. Nor has it spared those in power, the algorithm flagged the Delhi chief minister under the parent-age rule, classified the External Affairs Minister as unmapped, and generated a notice to election commissioner S.S. Sandhu himself.Those notices have since been cleared. As PTI reported on 25 September 2026 that prominent electors, including L.K. Advani, Jagdeep Dhankhar, S. Jaishankar, Rekha Gupta and Arvind Kejriwal, most of them flagged as “unmapped with the last SIR”, were cleared after officials, including BLO’s verified their documents in the field. Their names are reserved for the final roll due on November 4, 2026. About 33.13 Lakh of the more than 97 lakh electors on Delhi’s draft roll have been identified for discrepancy notices. The report does not say whether they will receive the same field verification or be left to answer a machine-generated notice.(This blogpost is the first in a series analysing the SIR. In it, we examine the software systems behind the exercise. Part 2 will look at data collection, documentary burdens and administrative pressure and Part 3 will analyse the exclusion and failures of access.)This story has been republished from the Internet Freedom Foundation under a Creative Commons License. For our full coverage on the SIR and the issues it has brought to citizens, click here.